Unable to change Disney+ extra

[Stedent]

I am wanting to upgrade my Disney+ account from standard to premium, but in the extras page in My O2 it's says 'You can only edit this extra once in each monthly billing period' and there is no option to change it. The only time I have possibly made a change is in May when the new pricing plans were brought in and I opted to stay on the standard plan, so is definitely not in this billing period. 

Any suggestions? 

[MI5]

@Stedent 

You need to contact O2.

Message them on Social Media. Facebook (https://o2uk.co/O2CFB) , Twitter (X) (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) or give them a call on 202 or 0344 809 0202

Guide: How to find help & contact O2 

Guide: Adding and removing O2 Extras