Anyone advise please:
We bought an iPhone 6 in Sep 2014 and availed to the promotion of returning the iPhone 4S for $200 credit. When we returned the iPhone 4S the AT&T store personnel we returned the phone could only give us $40 credit at that time and promised the rest credit ($160) will appear on our bill. He gave us the promise in writing on the Device buyback receipt.
This happened on 12/29/2014 - it has been close to 2 months and no credit. He even gave me his email and phone. No response to email or phone and letter to store manager goes unanswered. Very surprising in the hotly competitive field for post-paid wireless customers.
Any advise on how to approach this will be greatly appreciated.