See this Magix comment in the News section of the forum on the requirements for card payments.
Have you checked with your bank if the purchase has gone through?
If the purchase has gone through, you would have been sent an email confirming purchase, your serial number(s) and a download link, these often end up in the email Spam folder - have you checked there?
If the order payment did go through and there is no email, then contact Magix by email to infoservice@magix.net
. . . . cannot import my songs from I tunes . . . .
If you purchased the songs from the iTunes Store they may be DRM protected from use outside of registered devices to play them on and use in other software.
It the music was purchased under iTunes Plus then you may need to copy them to a folder that is not controlled by iTunes.