What happens when you try?
What exactly does "totally unsuccessful" mean?
Any error messages?
What if you use the website instead of the app?
Any difference?
When were you last able to successfully buy a membership plan?
Is your payment card still valid, not frozen via your online banking, and there are sufficient funds in the account if it's a debit card?
If you need to contact 48 support about this then see the links in my signature below.
