Unnecessary billing due to contract termination

I terminated my contract with ADT Security not because I was moving to another property but mainly because of their poor response time. An alarm goes off at 14h00 and they send a response car at 23h00 when I was already in bed because they didn't dispatch a vehicle at the time alarm went off. A full month notice was served in time stating that I will be moving out of the house at the end of February, I was billed on the 25th of January for the month of February. On the 1st of Feb I received an statement of account and I called ADT to confirm if they are going to bill me again for the month of March, I spoke to Ashveer Dewcharan who confirmed that I won't be billed because I was billed on the 25th of Jan 2016 for the month of February and he also confirmed that My Account no DIR069 was closed (this is recorded). Come the 25th of February I was billed again under a different account number jhdir00073. Ashveer Dewcharan and the team cannot give me answers as to what happened in this regard. Now ADT doesn't want to pay my money back.