cancellation of acc not clearly stipulated

My contract was cancelled on 24 feb telephonically. I was told last debit order will be on 1 apr 2015. You have now twice tried to deduct money from my acc. Your customer service told me I should have been told that you would deduct twice due to the first month of my contract being given credit in advance before payment. No one told me this. Dig up your recordings to verify this. I will not pay for something I was not informed of. Kindly stop debiting my acc on random dates because I'd like to have a clear credit at my bank! I will also be porting my nuimber to another company because I have never had such bad service in my life! I have been a loyal virgin mobile customer for many years. This is just a slap in the face. I struggled with bad signal for years but stayed loyal. Enough!