Hi Framo71,
Welcome to the Community Forums! Thank you for your post.
I'm sorry to hear you've been having issues with your mobile services after returning home from abroad. Did you make any chargeable calls or texts during your time away? It's possible that you've reached your credit limit and your account has been barred as a result.
Do you get a message when you call 789 from your mobile stating that your account is barred?
Beth