Hi there, am in need of some help

I have a 57 reg fox that has developed a fault, been to the dealership twice and the best they can come up with is "are you stalling it" or "its possibly that its been quite cold lately". Not very helpful for something thats on face value seems quite dangerous.

The latest occurrence:
The most recent time instance was on a short drive to the supermarket. On pulling out of a junction and starting to make progress down the road, a loud beeping noise could be heard, then the ABS and Handbrake light came on....a few seconds later the steering wheel locked, shortly before arriving at a fork in the road, giving the driver no choice but to take the left fork which was kinda 'straight on' and bring the car to a stop and re-start it.

Additionally each time this happens the clock resets, and the trip counter returns to 0.

The dealership say they have checked the computer and say there isn't anything in the log. They have had the car all week, and don't really seem to be investigating anything

Is anyone maybe able to share any thoughts or suggestions?

It seems to me that something 'brake' related is failing and the computer is shutting down and reseting. But not sure what could be causing it.

Any help greatly appreciated.