Exceptionally poor service to very long time customer.

After a lightning strike on our home, and 5 days of waiting a technician visited and told us the alarm failure was not from lightning but from wear & tare on the remote receiver unit.... It is a rental system so it is their responsibility to maintain it! 20 days later, having unsuccessfully trying to communicate with ADT, I called in another local alarm company, and wrote to ADT to terminate our account. They terminated with immediate effect but continued thereafter to take our monthly subscription fee & the annual radio fee. Now they send us a bill for the callout where the technician did nothing.... I cannot contact them, they just don't reply to emails and from the nice telephone operators I know for sure the stairway to heaven has been replaced with an escalator as that is all they ever do... "Sorry Sir, I need to escalate this matter......."