If you don’t put valid info into the Devex (Tipalti) portal, then you should be refunded the Robux. I guess you can try putting invalid data in.
(Make sure it is actually invalid though, so that it bounces instead of going to a random person).
Note that it may take up to a couple of weeks for you to get it back.
You can also try just contacting devex@roblox.comRoblox Support, but I haven’t tried contacting them [about devex] before.