Not familiar with the site / app. If it's an IP ban you might have to bitch at your ISP to change your outside IP. If it's based on your phone number / phone you may need to change your number or get a burner phone.
Pawn shops can be good to grab meh to decent Smartphones for under 150-200. If you're just using it for one app your banned from you don't need something super good imo.