stop running debit orders if and when you please

I have been trying since the 5th of august to tell elite mobile their debit order did not run from my account the beginning of august.I sent the bank statements to prove it.No one could be bothered to sort this out.I had to constantly phone every day.Just to be told on friday they want to suspend my line as my debit order did not run for beginning of june 2015 when my bank statement clearly shows it did.after eventually today getting through to angie one of the managers i explained again but then to to hear from chanel that it was indeed their mistake for not deducting but will now deduct again on the 15th which in fact is a saturday so they will only deduct on monday the 17th of august.Ok now i mean really is this what i agreed to>I SURELY DID NOT for them to take when and if they please.When i requested to cancel today i was told i would have to pay a cancellation fee.Are they kidding me and they also refused for me to pay the money they have not deducted in to their account.Is this company honestly competent in their dealings.I dont think so and i am very upset!!!