Insurance versus non-working item

Hi, I ordered a Baumatic dishwasher and took out cover at the same time with Baumatic. When the dishwasher arrived it was missing a spare part - in the end, I waited six months (and many many phone calls later and three engineer visits) before getting them to agree to send me a new dishwasher. A different model as I was told the one I had ordered was no longer in production (hence the lack of spare parts perhaps!). Anyway, my query is about the insurance. Shouldn't I have been able to claim that back? Why was I paying for something that wasn't actually working. If anybody can shed any light I would be grateful. Also, just to let you all know - the replacement Baumatic broke down so many times that now I can't be bothered to call in the Engineer and wash everything by hand!