I certainly do agree that you should request repayment of the fee you paid for transporting the overweight luggage. After all, the bags were lost and not transported, so you didn't get the service you paid for. I would try a polite request to customer service by email. I haven't had a serious complaint, but I've written two emails lately, one for missing miles, one a compliment on an exceptional employee, and the replies were super quick -- I'm going to say less than 24 hours. It will take longer than that to issue a repayment back to your credit card, I'm sure, but might as well get the ball rolling.