How do I switch from a Pay monthly plan (well past the contractual period so no problem there) to Pay as you go? There doesn't seem to be any option to do so within the account. 'Change plan' doesn't offer PAYG options. The only other option is 'End plan'. It's important to me to retain the number for PAYG so I don't want to go ahead and cancel the plan unless I'm sure I can keep the number.