Was this your first membership plan purchase?
If so then it's presumably the one-time activation fee of €12.99 in addition to the plan price of €12.99?
€12.99 Plan
This €12.99 Plan is only available to new 48 customers who order their 48 SIM and purchase a €12.99 Plan from the 5th April 2022. A one-time activation fee of €12.99 applies with the first plan purchase.
If that's not the case then what does your Transactions page say about your recent payments/purchases?
Does your Buy Plan page list any upcoming membership plans?
If you need to contact 48 support about this then see the links in my signature below.
