AA insurance give me bad night's rest!

Yesterday I got a call from a lady and she said my premium didn't go off on my bank. I told her I sent a letter to AA Insurance to request the change of bank details. She then said she would change the bank details and I also asked her to make sure it is the 25th of every month. I said they can immediately debit the new banking details. She said there would be a pro rata amount I must pay. i said I paid last month so I am paid up to the 30th of June and that if they debit on the new banking details I will still be up to date, She was very rude and would get back to me. The phone rang a few minutes later I think three times and then stopped.

This morning I wake up to find that AA sent me an email saying they acknowledge my cancellation of insurance...what the hell?