wrongly built momsen

Bought a momsen al429 from Westdene cycles 17 Jan 2015.<br> Did a couple rides and my chain got stuck in my rear derailer pulling it into my back wheel. Broke the dropout, derailer and damaged the rear wheel. First didnt know what happend till i inspected the derailer and saw that the chain was installed wrong rubbing agaist the derailer sharpening the edge till it got hooked by the chain. Took it in to westdene they didnt want to listen as i wanted to explain what caused the probblem. Spoke to david the rep from momsen he says its out of his hands they dont supply the bikes build so its westdene's problem. Westdene says they get the bikes from momsen they only fit the handlebar and wheels. After a long fight they now say they sent the derailer to shimano and the wheel to momsen for repairs and that momsen reps came to see the bike. I phoned David he said they never showed him the bike. I also sent david pictures of a vipa on the showroom build the same. I dont think its fair that i now sit without a bike and not getting a answer from westdene or momsen