I have lost my phone

[TonyP1]

I need a replacement phone 

[Enlli · Accepted solution]

First

Guide: Lost or Stolen O2 Device? - How to Report it 

If you want a replacement phone you either need to contact your insurance provider, pay off your present contract and take out a new one or buy a new handset outright

[Oxonian]

@TonyP1 

I am sure that the staff in your local O2 retail store will be delighted to help you :-

Store locator | O2 UK | Find Your Nearest O2 Store

https://stores.o2.co.uk/