Apple Watch cellular set up problem

[Fabienne]

I have been desperately trying to set up my cellular plan on my apple watch all day. When I go onto the apple watch app on my phone, and then go to set up mobile data, it tries to take me to O2, but instead spends about a minute trying to load and then gives the message: 'Oops, something went wrong. Try again and if the problem continues call 202 for free from your O2 mobile, quoting reference code 37'. I have tried calling 202 multiple times but I cannot get through. I have also tried contacting customer services online but I got told to call 202 again which still wouldn't work. This has been a nightmare. Can someone please tell me what to do/ how to sort it? I have tried re-pairing my apple watch too and that didnt work either. Both the watch and my phone are fully updated. 

[MI5]

@Fabienne 

You need to contact O2.
All numbers are in this guide Guide: Coronavirus Community Help and Support 
When you call, you will be asked for the reason you are calling.
Stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
You can also try saying "Upgrade" or "Fraud" to be connected to an advisor.
8.00am is the best time to call if you can.