BMW Car that changes gears to PARK when I drive

I bought a car at Randburg BMW March 2015. The car changes gears by itself when i drive. It happened two/three times as i drove within my work premises. On or around 22 April as i drove in N1 Highway the car changed gears into park and it stopped. I was almost was hit from the back and the other cars almost bumped into each other. It was a scary and traumatic experience. I called the saleperson and he said i should take the car to a BMW service center. The following day i contacted BMW On Call. They towed the car and took it to Hatfield Service Center. The Service Center checked and informed me they had updated the software. I informed them that i was scared to drive the car but the person assured me that the problem was now sorted. On Monday, 7 September i was driving home and the car changed gears and stopped. It was during peak hour and the cars behind only hooted at me. I informed BMW Customer Interaction, they gave me a reference number. The Service Centre sent a driver to collect me and i called BMW Customer Interaction around 4:44 to inform them that i am scared to take the car. The person that i spoke to said the car has been fixed and they trust their service center.