go to the o2 support site and type in complain then follow the information there.
Put the facts in an email to the complaint review service.
They may be able to help you or not but that is the top level complaints department you will get an automated email confirming reciept and then 7-14 days for them to come back to you.
iPhone 11 Pro 256gb on unlimited data
iPad Pro 12.9” 2020 256gb refresh o2 family discount
Apple Watch series 4
My first mobile was in 1995 a CM-R111 from sony on Cellnet.
Wincanton South Somerset (Full 4g 3G 2g indoor coverage) Remember we are all customers here not customer services