Debit order deduction after contract cancelled

My contract expired in May 2015, I went to the service centre to cancel it on the 19th of May 2015. End of June and August 2015 money was deducted from my account even after the contract was cancelled. From the month of June I did not receive a top-up but they still managed to deduct money from my account. When I went to the service centre On the 1 September 2015, I could not get assistance and they referred me to the 808 number. When I called the number, they promised that the money would be transferred back into my account within five working days and today's that this not been done. <br> <br> The reference number: ***