Phone broken?.. i9195 LTE

Okay, so ive had my I9195 LTE for some months now, just a few bugs here and there, but nothing major.. till about a few days ago..

Suddenly i cannot make OR recieve calls, it just instant hangs up, and says "Conditinal Forwarding active"

Now some info below here..

Ive tried..
Reinstalling ROM
Installing new Baseband/modem
Going back to stock
Formatted and done all of the above
took the battery out overnight to see if it worked, then did the same as above.
took the battery out overnight AND the SIM card and did the same.


None of these fixed the issue.

Oh and i tried the SIM card in my old S3 mini, worked flawlessly.


..Any takers?