If it is an e-cert, then even as a Gold I didn't have to pay any redeposit fee. In fact, I didn't even have to talk to anyone. I made the reservations online and cancelled it online and the points were automatically redeposited.

If you have a paper certificate, in general Plats don't have to pay the redeposit fee. Back when I was a Plat, I probably returned 3 or 4 award certs and never had to pay. I haven't had to redeposit a cert as a Gold though, so I don't know if it was a "Plat" benefit or a general "elite" benefit.