2003 Mitsubishi Montero Sport L died and won't start

I just had a new gas tank installed and a gas/exhaust solenoid replaced, it was running great for about a day, then randomly died while driving like the engine was not getting fuel. The car did not lose electrical power and cranks just fine. Tried jumping it and also adding extra gas in case fuel gauge went faulty during repair, but that is not the problem.
When it started dying, the accelerator just slowly stopped working until the car shut off, and simultaneously the brake and battery warning indicator lights came on and are still on when key is turn forward. I can hear the fuel pump working when I turn the key forward. Is there something the mechanics could have forgot or neglected to do during the gas tank or solenoid replacement? I think they screwed it up.
Answers