Feels like a shortage of gas or power in 2005 Kia Rio5?

I was in an accident last winter and it took about 4 months to actually get my car in and repaired. During this time there was never any issues with my car, just damage to the body. When it came out of the repair shop I went on a trip that involved driving through the Canadian Rockies and that was where my issues began.

When I press on the pedal it's like my car isn't getting any or not enough gas. It will rev and move, but not very fast. I have trouble getting my car up to 60-70+ km/hr and when I do the car will sometimes continue to rev at 3000 rpm. At the same time I'm having these issues if my car is in drive and to a complete stop and I lift my foot off the break it won't roll forward like it should.

This happens most often when I'm on the last quarter of my gas, or sometimes when it is really hot. It will begin when I initially start the car or if I have slowed to a stop and go again.

Liquids have been checked, Kia Motors repair shop told me there's nothing wrong with it. They did however reset something on the computer that was turned off. It never helped.

Sorry this is lengthy. There's just a lot of details.