Rodeo won't start

After the car was sitting outside during a few days of rain, it died while driving that night. Maybe 10 minutes later, the car started back up no problem. Drove fine the next few weeks, but next time there was rain and the car was outside while it was raining, later that day it died again. This time it would not start back up. It turns over fine, and eventually (waiting for 1 hr) will start, but then dies seconds later. Took it to a garage and they said it was the fuel pump. So they fixed it, and 2 miles from the garage died again. Same story, turns over, won't start. First, any ideas what else it might be? Second, what recourse do I have with the garage? If it wasn't the fuel pump, can I get any money back for getting that fixed when it possibly wasn't necessary? Do they owe me anything for the hassle, getting it towed back, etc.? Please help!

could be a ground problem

I went through the same thing with my old Chevy S10. That is the dealer replaced the fuel pump, due to the truck dieing. 2 wks later the same thing. To changed the OEM cap and rotor (160k; so it was way over due) and all was better.

But you don't have a cap and rotor.

So check your ground points, maybe have the battery and alt load tested.