Why is my Apple Watch unable to connect to the O2 network?

For weeks now I have been attempting to connect my Apple Watch to the O2 network.

I am continually told that the watch is setting up on the O2 network and after 24 hours call 202 from the phone and quote code 08

I have done this repeatedly and at the end of every conversation some lasting more than 50 minutes I am advised to go to the O2 shop.

This has been done x3, on the last occasion I showed them the advice to get a new eSIM but was told this was impossible as the phone did not have a sim!!!!

Any help would be MOST appreciated

[Re-Titled by Moderator]