Problem with SBC

Hello. I drive a 2006 MB E350 base model. I have had the car for almost 2 years now. In the past 3 months, the SBC/ABS on the car has failed several times. The dashboard goes red and braking power is severely reduced, ESP warning etc. come on.

I have a dedicated MB mechanic and after the last incident, the car has been with him for almost 3 weeks now.

He took it to one of the best diagnostic centers in town and after checking, we were told that the 'body' and 'leg' sensors, and that would be the ABS sensors were bad. We had the 4 of them changed. I did not think that this was the issue and so I asked him to do a careful check. 

Eventually, they found that the 'brain box' for the ABS was bad and both the brain box and the SBC were changed. Worked fine for the few days of testing. Took on a long distance drive and came back, and on the way back, the a brake warning came up and said to return the workshop.  He checked and one of the sensors needed to be replaced and he did. He then took the car to clear the codes and he felt it was okay.

On his way to return the car to me, the SBC/ABS failed again. 

I need help, counsel, and advice about what to do or how to proceed with resolving this issue, short of just selling the car for scrap.

I look forward to your responses.

Thank you.