Bought invalid PDF tickets

Bought a pair of tickets and they were instant download PDF tickets, it was a ticketmaster ticket but a printout pdf version and when I scanned it to go to the Vegas Cirque du Soleil show, they said the tickets were invalid. Contacted stub hub right there and then but halfway through the chat, the data cut off and chat stopped working. Contacted them again the following day via chat and they said the case has already been escalated and no further action is needed. I called them again today via phone and they said they didn’t get a case going yet but they said they can escalate it and get a refund. They did ask me questions such as which gate I entered at, and if I got a screenshot or picture of the invalid tickets. I didn’t get a chance to take a picture or ask venue for proof because I didn’t know that was required and I thought stub hub has a seller protection. What’re the chances I get a refund from these invalid PDF tickets? And what’s the general time frame? I spend 400 USD total.