Just to make sure I called T-Mobile, got the call escalated to higher tech support and everything was fine on their end both with the system and my account.
As I figured it was my equipment. Not sure how it happened but somehow a settings changed itself because I know for a fact
that 1) I didn't adjust this settings as I've never
been in my SMS settings since receiving the setup SMS from Nokia.com and 2) Nobody
touches my phone but me and it's w/me 24/7.
The settings was in Messages->Options->Settings->Text messages
The third option down is Character Encoding and for some reason this was set to 'Reduced support' which didn't sound right to me so I set it to 'Full support' and for some reason this solved it (it seems so far anyway).
If you need further help, I’m available over the phone at https://www.6ya.com/expert/jason_70466cb634a57543