deplorable service

i have a mechanical warranty policy with GENERIC and the debit order came back because i closed the account.I received an email to ask me to pay the account or if they could re-run a debit. I explained to them that my account with my previous ank has been closed and i informed them of my new banking details and asked them to run the debit. I get a mail today to say that my policy is cancelled due to me closing my old bank account.What ******* is this.i would like them to shaow cause as to why this has transpired and if not re-imburse me for the 4 months i have paid.