My Apple Watch doesn’t won’t to connect. All it says is “this Apple Watch cannot be activated for service. Please contact your carrier or Apple care”. I’ve contacted my carrier and Apple but neither of them could help me. What should I do?

I’ve done everything I could. The problem doesn’t seem to come from the iPhone since it’s on the latest version, I’ve reset it and even tried to connect the watch on three other iPhones who also are on the latest software. The Apple Watch also isn’t activation or iCloud lock. For some reason the serial number isn’t working anymore and I’m unable to provide the IMEI number. I really need help cause I can’t return the watch and I’m unable to bring it to a physical store due to COVID-19