Terrible service

I have called the ADT call centre 7 times to get historical statements / invoices for my ADT account for the 9 months from December 2016 to August 2017, and have not received an appropriate response. I either get sent the wrong information or I don't get sent any information at all. I tried to escalate this to a manager in the accounts department and got an answer. I was also promised that the manager would call me back to resolve the issue and I have had no call. This service is unacceptable and been a complete waste of my time. I wasn't even sure how to complain to ADT and so I have turned to Hello Peter for the first time! Hopefully this complaint will get my issue resolved. I experienced these service issues over the last two days 5-6 September 2017