A family of three, inclusive of their 10-month of baby, were the last to board on our flight from London to New York, on flight BA 185. They boarded and spent roughly 30 minutes running up and down the aisles, passing the baby around and creating major annoyances. The parents tried to store their child ON THE FLOOR of the flight, and even hit the baby when it started crying, as they were bringing her back up to the chair. After 35 minutes of back and forth with the crew, the crew agreed to let the parents place the 10-month old baby in bassinet, but in a different row from us, for the flight after take off and before landing. Throughout all of this, the wife is sitting looking aimlessly at her screen and not engaging with anyone, while the husband is being critical of everyone, screaming loudly, and acting arrogantly towards the flight staff. As the cabin is being prepared for take off, the husband, who is sitting next to me, turned and in a very alarming and manipulative way said: It is going to be better for you to switch seats. Because I didn’t have a first class or business ticket (due to lack of inventory), I resorted to paying extra money to reserve my seat. Hearing the husband ask me to switch from my aisle seat to the interior middle, and be in between the husband, wife, and 10-month old baby seemed like a joke, and I respectfully told him I’d like to remain in the seat that I was assigned. For the next 3 hours, the couple is loudly talking with each other. They had no concept of talking quietly as to not disturb their fellow passengers, and the stewardesses were not helpful in asking them to settle down. In addition to the loud conversations, the guests had no concept of personal space. The husband elbowed me countless times, slept on me, put his clothing on me, and even used the area under the seat in front of ME to put his feet. At a point during the flight, the baby woke up and began screaming. The wife was fixated on the map in her entertainment console and outwardly ignored the screaming baby while the husband was in the bathroom. Multiple passengers began looking around, trying to locate the parents to come sooth their child who is now screaming, as a few minutes had passed, when the father jumped out of the bathroom and began soothing the child again. The wife remained unbothered and once the child was finally calm, the father begins having a conversation with his wife over me and the man sitting infront of me, yelling at her for something. She passed him a pillow and he went to go and sleep ON the emergency exit lever. A flight attendant walked past, looked at him, and kept going despite the serious risk this could pose not only to him, but to everyone on the plane. Suddenly, the flight encountered turbulence which promoted the child to begin screaming. Again. The wife begins screaming over us to the husband to wake him up and get him to tend to the baby. He doesn’t answer her and the baby miraculously falls back asleep before our flight attendant returned and ask the couple to take the child off the bassinet due to turbulence. I get up to use the bathroom and find that the husband is sitting in my seat, trying to once again place the baby on the floor. Once the baby began crying, they brought her back up again to their lap. Throughout the flight, I had to stand up for the couple over 35 times. I was not able to sleep at all due to the constant screaming, crying, loud talking, and constant movement to appease the child and the parents. At one point, the flight attendant had to literally hand the baby over to the parents, over me and the man in front of me, because the couple refused to get up. In addition to this, there were two other small children in front of me, and one behind me. I was surrounded by very young children who spent the entire flight screaming and bothering those around them. There was a 15-minute period where the two kids in front of me were standing up, facing me and yelling, while changing the content of my TV screen multiple times. The young child behind me at one point didn’t know how to open the bathroom door and began screaming bloody murder. I fly for work multiple times a week across multiple airlines, have flown over 100,000 miles in 2023 alone, and I can confidently say that this was the worst flight experience I have ever had. Despite my multiple requests to switch seats, the flight attendants claimed there were no available options, even though there were visibly empty seats in my class. I upgraded my seat for a more comfortable experience, but the reality was far from British Airways' commitment to customer satisfaction, as ironically depicted in your onboard collateral. The entire flight, the entire crew was completely unbothered by my complaints or my experience. They did not once try to help me in the situation I was in, or offer any type of assistance with resolving the issue, despite the various options they had available to them. I would also be remiss to disregard the blatant disregard for safety displayed by the cabin crew. They allowed a 10-month old infant to be sat away from its parents, allowed a man to sleep on the emergency exit door and lever, and ignored a child being placed on the floor for flight travel.