I Ordered some performance gas cartridges and was sent extra value ones instead, they had DPD collect the wrong cartridges in a timely manner. I made it clear I didn't want a refund because I needed the cartridges I ordered and they confirmed by email they would send the correct cartridges. A few days later I received a refund even after saying they were due to send them out that day when I had sent proof that the wrong cartridges had been collected. I would have accepted an explanation that they didn't have the performance cartridges in stock for example, but instead I was lied to. The matter has now been taken to trading standards.