Did you verify you qualified for the promotion? Particularly did you add a new line of service for one of the phones?
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.
To qualify for a BOGO you need a new line of service and wait 2 - 3 bill cycles. If you haven't received credits by then, you either didn't qualify or will have to call CS to have a form submitted to fix.