If you qualified for the "second month free" bonus then you should have received €12.99 cash credit to your account which you can now use to buy your second month's membership plan.
If you did receive that cash credit then it should be visible on your My48 account Dashboard:
And you can then use it to buy a membership plan:
If that doesn't clarify matters then please clarify what the issue is.
If you need to contact 48 support then see the links in my signature below.
