Shockingly bad service

I had such great service for the duration of my contract with Discovery Insure, until I had decided to move elsewhere due to a more competitive offering. I advised them a month in advance that I wished to cancel my policy and received a notification that I would be contacted by their client retention department. Nobody ever contacted. I simply received notification that my query had been resolved. However, they still collected the full debit order at the end of the month. I called on the 28th of April and was assured that the funds would be back in my bank account within 5 working days. Nothing.... I called again on the 7th of May, I was promised a call back before 1 pm same day. Nothing... And I still don't have my money back. I have 3 other products with Discovery, including banking, but if this is how you treat your clients, then I'll rather take my business elsewhere. I'm truly disappointed.