transmission

Please someone help me! I can't take being riped off one more time! I just bought a 1993 satur sl2 from some friends of mine @ church, there was my first mistake cause they lied abouut what the car needed and I trusted them so 400.00 later with a new raidiatorI finally get todrive my car. for a day, as I'm backing up from a parking space my wheels just stop moving. all four tires locked up. The lame shop it sets in right now hasn't been able to give me one straight answer on why.I can't move it well couse the wheels won't roll. My question, when the guys were replacing the radiator could they have done some thing to cause this? Oh yea when I tried to back up my transmission was running like a river under mycar imeadiatly. someone please give me some bargaining material here so I stoped getting jerked around. Thanks:rofl: