Being charged for replacement receiver box lost in the mail

I found a $150 additional charge on my ATT Uverseve bill this month for a replacement cable box not being returned. The box was lost in the mail and ATT sent us a replacement one which we did receive and then used the box to return our broken cable box. We were told there would be no charge for the box lost in shipment to our apartment. I spent an hour and a half on the phone with ATT and spoke to 5 different people before someone was finally able to submit a claim that is expected to be processed in 72 hours. I will be billed for the box by then paying ATT an additional $150 for their mistake which is pretty ridiculous and unethical. Is there anything that can be done to correct the bill before I am charged?