Appliances online delivered twice within a week faulty washer, please HELP

[myself6]

A week ago I ordered a new Bosh washer from AO with next day delivery. From the first use it was obvious that something was wrong with it , it was making a very loud and not normal sound every time the drum was turning. I contacted them and they said I had to contact Bosh and use the guarantee to get an engineer to visit . At no point accepted themselves any responsibility as a retailer. The engineer confirmed straight away that there was a fault so I got a replacement. AGAIN from the first use there is the same and even louder noise. AO refuses to refund /replace without an engineer to visit again. They say that they have to make sure there is a fault and they treat me like an idiot as I wouldn't understand the noise or as I did something wrong with the installation. I said this is the SECOND time the same thing is happening and you confirmed the first time with an engineer that is a fault why do I have to go through this again? Citizens advice advised me that they are obliged to refund /replace as the washer arrived with a fault but AO replies that *citizens advice would advice me to my benefit but this is not how things work*. So TWO washers WITHIN A WEEK WITH SAME FAULT and AO still insist on engineer visiting first. All this is very annoying and inconvenient for me as I had to stay in waiting deliveries/ engineer , I still have to wait another engineer , spend hours on the phone with AO and Bosh and i still do not have a proper working washer.