I have also had problems with AT&T posting miles to my Marriott acct. I switched over in late April to get the 5,000 Marriott points. I had signed up late last year for 10,000 points and the points actually posted so I was anxious to try again. After determining that it was more than 6 months since I had left AT & T, the operator signed me up and said it would take 90 days for the bonus to appear. I received two small postings to my Marriott acount for monthly usage but no bonus points. I called this weekend and the operator said she will file a customer complaint form and that will take at least 30 days for an answer. They first stated I was not eligible for the bonus but reneged on that once I counted out the months for them.I switched later Saturday to Sprint and am writing to the FCC.
I guess I should feel lucky I ever got any bonus miles out of AT & T. Buyer beware

Paul