Billed by autopay for months after cancellation

I was a loyal AT&T mobile customer from 1996-2012, when we had to move to a rural area without coverage by AT&T and thus switched carriers.  We cancelled with AT&T.  Our previous bill had been about $260/month for a family plan with data.

I discovered in February 2014 that AT&T had continued to bill me via American Express for $60.91/month.  I called in, and was told that, while nothing could be done about the previous paid amounts, I would be credited for the remaining months and formally cancelled.

Then, I received a dunning letter from AT&T telling me I'd have to pay ANOTHER $60.91 or be reported to a collections agency.  When I called Customer Service, a supervisor named "Benjamin White" was hostile, rude, and demanded that I pay the $60.91!

AT&T never should have been billing me $60.91 after December 2012 in the first place.  The company owes me money--not the other way around.  

Since you've no doubt already classified me as LTV-1, I will pursue this with Colorado's Office of Consumer Counsel at the Attorney General's Office.  I will also be pursuing other remedies.

I'd like to avoid all of this; but, since AT&T continues to give me the run-around--and has threatened me--I am not seeing any other recourse.

Oh; and, by the way, I belong to a professional organization with over 1,000 members.  I will be reporting how I am treated on the listserv for that group.