I have just had my blower fan replaced on Tuesday while driving

What is your question?

On Thursday my car died after about 15 miles put on I was going 55 and I felt it jump buck kind of kept going then bucked again and shut down. I tried starting it a few times no luck after 15-20 min started up ran fine. The lights stayed on for battery and oil and then went off.I took back to shop they said nothing was wrong. Drove it died again and again this is not safe and need some help please and how to figure out if it is that that I need....thanks