I'm having an issue with the AC

What is your question?

I purchased this car a little over 2 weeks ago and when I left the dealership the AC worked fine and did up until last weekend. After driving approx 150 miles, the AC stopped blowing cold, the blower worked fine. When I got home, I took the car out the next day, the AC was cold but after a few miles it began to blow hot again. So every time I start it up, it blows cold but after a little while it blows hot again