Oh I see! Sorry, I should not have looked at that with my iPhone! Yes it does look like a bit of excess leather. I would make sure to ask and call the TB phone line and ask them about it to be sure that it won't be negative in the long run and or they might have one for you.
But to be honest it does look like it's going to wrinkle more as more usage has been done since, well, the excess leather is still going to be there. As the rest of the leather streches, so does that excess, which will probably still look like that! I'm not sure though, but I've had a similar experience...
If you ABSOLUTELY love this bag, then by means keep and receive the discount. If you cannot picture yourself being okay of letting this go, and if you can live without regrets, then by all means! If it were me, I'd get a refund just because no one can do anything about the excess leather :s