You can contact Offer up via twitter and get a response, they will ask you to Direct Message them on their twitter page or send and email to: firstname.lastname@example.org I've had responses from twitter but no response for my email. I'm assuming I won't get my account back but no big deal.
I've tried a new account, email, resetting my phone, fake GPS, etc, they don't work! The ONLY fool proof way to get back on Offer Up is to get a NEW cellphone & service ! Set up a new email & offer up account and sign on with your new cellphone! That's it!
Many people may think getting a new phone and service is a waste of money, but if you are one of the few people that actually DO make a lot of money off Offer up then a $40 a month fee (or less depending on where you get it from ) or even a second additional line on your existing cell service is worth it. I had 1 account with over 150+ items for sale, 87+ 5 star reviews & 100+ followers so getting back on is worth it for me. I got greedy and recently setup an additional account that's, where I screwed up! I was just banned a few days ago and now, I'm back online again!
PS: once you're back on again, keep just 1 offer up account! Good luck everyone!