Sometimes, they're great. Sometimes they do what has already happened to OP - they get information and do not apply any rational thought.

I had an issue where I ordered something, confirmed with company a delivery date as it was needed for a presentation. Company did not ship as promised, so I called and emailed telling them not to bother, do not ship. They shipped anyway, then wouldn't refund shipping charges. Had to go back to Amex three times asking what I could have done differently - was promised something, didn't get it, asked through all available means to cancel, then got the run-around.

Amex finally came around...