Just one thing, when you unlinked the old watch, did you click on "remove data plan" or "keep data plan"? There are contradicting steps out there.Once I gave them my new S7 EID and he swapped it over on their end, I went into the iPhone app mobile data and instead of 003 it just went straight trough without any errors, literally didn't do anything else. To check all was working I disabled my iPhones wifi and bluetooth as well as the watch wifi and the EE cellular kicked in just fine. Best thing to do is speak to someone else as some agents seem to have issues transferring the plans properly.
Called 150 then 1, 2, 1, 1, 2