Booked a holiday with TUI and contacted them on Monday the 18th December to add child onto booking, we had booked a room that accommodates 4 people, was told that everything was fine and given a price, however they encountered a problem with the flight as their system was down, however after several phone calls to tui this simple request has not been fulfilled, Phoned again today to be told the accommodation is the problem, last week it was the return flight, there is not a problem with the accommodation at all, another family group are booked on the same holiday with the same room and the same amount of people after adding one of the children onto their booking as they are twin boys. Have just spoke to them again to be told the problem js that when they added the child onto the booking they only added him onto the accommodation and flight out. Have spoken to someone who claimed he was a manager just now and he says he has contacted the relevant department regarding the flight as a matter of urgency so he should get a reply if we can give him 5 days. The customer service has been diabolical, promises of phone calls from them on 9 occasions not one received, told the issue would take 24 hours we are now 10 days later and the so called manager now tries to blame the holiday period for slowing things down. We are now in a situation where two children came to live with their father after a family breakdown and one is booked on this holiday and the other we have no idea what the outcome will be as we've been told so many conflicting things by TUI.