It can take up to 24hrs to fully change over to pay monthly, so your pay monthly mms might not be set up just yet . You will need to change your apn like mi5 said
For iPhone data boltons: idata.o2.co.uk Normal Bolton: mobile.o2.co.uk Wap: wap.o2.co.uk
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.
Currently using: Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)
It can take up to 24hrs to fully change over to pay monthly, so your pay monthly mms might not be set up just yet . You will need to change your apn like mi5 said
For iPhone data boltons: idata.o2.co.uk Normal Bolton: mobile.o2.co.uk Wap: wap.o2.co.uk