You'll need to post more information if you want assistance from the Community Forum.
What exactly do you mean by "topped up"?
What did you purchase?
Membership plan, add-on, cash credit?
What does your Transactions page say about your recent payment/purchase?
What does your My48 account dashboard say about your current membership plan status, expiry date and allowance balances?
The €12.99 plan comes with unlimited data so there's no way that you can ever run out of data (excluding roaming data) as long as you have an active membership plan and your APN settings are configured correctly.
Can you make/receive calls and send/receive texts?
When was mobile data working OK for you last?
Did you ever configure your APN settings for it to work?
To do this text "APN" to 50048 and follow the instructions here:
If you need to contact 48 support about this issue then see the links in my signature below.
