I'd expect no argument whatsoever from the vendor, that was a cold solder job, could have been caused by a few different things none of which are your fault. The part soldered before yours might have come out fine, the one after it almost certainly didn't solder at all and failed QC.
Yours was the unlucky one that mostly sorta got soldered, put in a box and shipped. An old school QC tech would have pulled the few that went through before total failure happened for a proper look over, given the port a wiggle and had it break off then and there. But I'm guessing this is all done by non human type things these days.
No part of the Pi board should get anywhere near the melting point of solder regardless of what you did with it.