Shockingly bad service - Defy clearly do not want customers to buy more from them

Our dishwasher (just over 2 years old) keeps tripping the electrics. Defy service engineer has been out twice and each time blamed the problem on the water waste trap under our sink, into which the dishwasher outflow pipe is connected. I have replaced and lowered that trap (with one designed for washing machines and dishwashers), at considerable expense and trouble, but the problem remains. The original trap was used for the life of the dishwasher and the previous owners of our house used the same for their dishwasher - it makes no sense that the trap was the cause of the problem. More likely, water is getting to the electrics inside the machine - a deteriorated seal perhaps. I requested another call out on Monday and was informed that "we have escalated to the technician..." It is now Wednesday and, as yet, I have heard nothing further. I tried logging a complaint and all I got in return was: "As per update from the service manager, the installation is incorrect. Kindly contact a plumber for further assistance". I tried phoning to escalate but it seems there is no one who deals with complaints in Defy - not surprising, looking at all the previous reviews, they would need a large team for that. Just shockingly bad and in breach of consumer rights: selling products that are not fit for purpose and refusing to provide timely service.