Its' not ITV's contract to give. Remember the local ITV company only controls P600-699 (and 888) on the service. Teletext Limited are a completely seperate company with a seperate licence (one which applies to both ITV and C4, though Five's service is also operated by Teletext Limited, it is another seperate licence).
So it is Teletext Limited you should complain to, not ITV...
Sounds like this is a local fault to your area. Teletext for each of their regions is generated at transmitter sites. Chances are that the computer at your local transmitter has gone wrong.
Aww, ITN supply the news for Teletext. It's like the old days when they did that for ORACLE. I wonder how long it will be before ITN put their logo on every news page like they did on ORACLE.