I've had sales canceled for this reason, however it wasn't that close to the start of the event. You are not going to get Stubhub to do anything for you. Good luck with the AG, I doubt they'll be interested enough to create a case.
Yes I had this exact problem about two weeks ago. I reached customer service an told them that this situation should never arise: that if they receive a payment that can't be approved immediately they should just cancel the sale and keep the tickets listed. The rep tried to give me the runaround, but I insisted they escalate the issue to their superiors, to prevent this scenario in the future. Whether it will ever be addressed I have no idea. Ever since Viagogo acquired SH from Bay customer service has gone downhill.
yes this happened to me as well. no soultion was done by the time they "relisted my tickets" the baseball game was over.. i lost 5k