Yet again ADT has let me down??? What do I do NOW

A few weeks ago I had issues with ADT non existent service. I had to resort to Hellopeter and my query was resolved. Further to that complaint I received written confirmation that my debit order date will be amended to the 25th of every month....Last month ADT debited me on the 11th of September??? ***. This month it is already the 28th and I still have not been debited??? Are they going to debit me in the middle of the month again?? What if I don't have funds in my account at that point who will be held accountable??? I am really gatvol with their pathetic service. I am so gatvol of their service which does not existent I will actually incur early settlement costs to be rid of this useless company. I copied the sales manager in an email on Monday regarding the above as well as the sales person and 3 days later no response from anyone..