Your post was blank @MirelaG6784 and the subject line doesn't really provide much information.
If you want assistance from the Community Forum then you need to describe your issue in detail.
What exactly are you trying to buy (membership, add-ons, cash credit), how are you doing this, are you using the app or the website, what happens/goes wrong, any error messages, etc.
Does it make any difference if you use the app instead of the web interface, or vice versa.
If you need to contact 48 support about this then see the links in my signature below.
