Very poor customer service!

My car was written off in August (a month after I took out warranty cover) and I submitted a cancellation request on 1 September which is supposed to be processed and a refund given within 21 working days. Long story short, it’s now 70!!! Working days and still nothing! No one can tell me what the delay is, I have sent the required documents to various email addresses and spoken to 7 different customer service agents, each one promising to get back to me and failing to do so!