Thrifty made a mistake and then cheated me

Took forever to get my car at LAX. Had to change vehicles a few days into the rental, at which point LAX changed my return time in SF. But when I arrived on schedule to drop off in downtown SF, the office was closed. Apparently LAX didnt know the closing time in SF. Had to go back to SF office 7am the next morning, but Thrifty charged me an extra day and a late fee - $91.33. I followed their instructions and they charge ME money for a THIRFTY MISTAKE. I am still trying to get my refund. Will never use Thrifty again.