95 Saab 900se Convertible A/C Problem help please!?

ok so when i bought the car the A/C was working just fine, then the day i picked the car up and drove it home, i was showing my grandfather the car, as i went to leave, sense i was still learning how to drive stick and his house is on a hill, i stalled out about 3 times, on the 3rd stall, i heard a extremely loud pop and white smoke starting coming out of my hood. i immediately shut off the car and opened teh hood. at first we saw green stuff on the ground and thought it must of been a radiator hose that burst or something. we called up the guy and he came over and looked at the car. he noticed the green stuffo n the ground is not anti freeze but its freon, and that the Hi-Pressure hose went. he said he will fix it NP.

i dropped off my car yesterday and he replaced the high pressure hose and refilled the freon, also checking everything else for problem, he couldnt find any, but now the A/C is extremely weak and the cold air only comes out of the driver side(COLD), the middle vent(semi cold) & passenger side vent(not cold at all its like outside temp). also as you drive the A/C will go from cold to warm to cold to warm, around every 8 to 15 minutes.

he said he will look at the car tomarrow if i drop it off again as i had to take the car i have to go to work.

anyone has anyone else ever had this problem? the AC system is a climate control, and the compressor is new(from what he says was installed almost a year ago). Hes a friend of the family and hes own a repair shop so i know hes not ripping me off. just wondering if anyone has had this problem before?