all telephony functions ... are disabled due to a communication error - anyone else experiencing this problem?

wifi in the other hand is fine.

The phone has been working fine, up to a couple of days ago.

I'm in the UK and my network is T-mobile... I understand that t-mobile has been merging with orange and lately i have been receiving messages saying that i can also use orange services, but when i tried, i receive a message saying that they experiencing technical problems, which makes me think this could well be a network issue. T-mobile today proved to be completely hopeless with their automated phone system and lack of information about network status... at one point pointing me to the coverage checker page, the only person i been able to speak is with sales as i have not been able to access the customer support without the telephone, the number they have to call them from non-t-mobile phone suppose to be the same as when you dial 150 but has the technical support option is missing from the menu option, what a nightmere, just to check if there are any reports of network problems, even vodafone offer this information to customers.

If you experience this before, how did you fix it?