When I flip a house I have multiple returns/refunds on my Amex cards during the 90 to120 days of remodeling and it's never been a problem. Earlier this year I had to return a commercial Viking stove that was damaged during delivery and I had already paid the Amex CC I charged it on and Amex didn't give me any troubles with the large refund amount. I guess it could be a YMMV thing.