Locked up Apple Watch

I upgrade my iPhone Xs to iPhone 11 Pro. During the process I cannot reconnect to my Apple watch. It keep asking for my passcode and I forgot. I tried the suggested process to reset the Apple watch but it always goes back to the locked screen. It must be that the new WatchOS fixed this loophole. Can anyone help? I believe I have a backup on iCloud but its useless unless I can pair the watch with my new phone. Unfortunately I have already erased my old iPhone. BTW I have the original receipt if that's needed to have my watch reset by Apple store.