Cancelled Policy

I signed up for a policy with Virgin Money Insurance to deal with scratches and dents for my car. On inception, I was told that this policy was linked with my main insurance and any changes made there would automatically be app**** to this additional insurance. Same policy number was used. I have moved a few times in the last few years and each time I changed my debit order, my policy got cancelled. This was rather annoying because the reason given was that no such account, when they attempted to process the debit order. This is despite the fact that the main insurance policy had no such problems. I have recently noticed once again that the R84 is not coming off my statements and queried this with the insurance agent who contacted me when I once again changed my debit order details. She once again notified me that it was cancelled in June 2015 with the same reason. They made no attempt to contact me and instead made my policy lapse when the fault was entirely theirs since these policies are linked and hence should have access to the same information. Despite me asking for feedback from the nice young lady, no one has contacted me yet and this is very unprofessional and unfair