Radio/tape Cd Player problems of the 2004 Nissan Murano

Bought car from bill askew in February 2015 around tax time. . . Went to gas station and car wouldn't crank. Call bill askew and notified them. . 5 min later the vehicle came on. . Went to dealership and they replaced a battery. . . Running good for a couple weeks. Check engine light came on and needed a electrical equipement. . . Radio and cd wouldn't work. That was replaced also. . . In March got a oil change at the Nissan place. . I was told that I have a oil or gas leak. . Notified bill askew. . . No reponse but everytime I take the truck to the dealership I got it from they turn off the check engine light and said it was nothig. . Today September 5th 2015 the truck turned off while backing up, the truck stalled in the middle of the high way while my daughter was in the car with me. . Cars blowing. . . 3 min later I turned it on and I call bill askew and notified them about the problem. . It was after hours and im currently waitning on a response.