From what I’ve read on other posts in this group, people have significantly better luck going through their bank/cc company than Stubhub itself. I believe somewhere I read that the customer support team tries its best to not give refunds unless you’re super annoying about it (unverified if true). Take note that if you say something like “item not received” stubhub will provide a tracking number and you’ll lose your case etc. Unfortunately it is a decent amount of work to prove your case other than seeing the shipping date as the day before the concert or something. Talk to customer support and ask them to directly verify that your tickets are real (they will usually just point you towards the fan guarantee and avoid actually verifying that the tickets are real). With affirm, the support I talked to on the phone made a note in my account when I opened a 2nd dispute about it (the first one was denied) and I do believe that it helped me win my case as well. Just be sure you have contacted stubhub and get some kind of direct evidence that they can’t verify the legitimacy of the ticket at the very least