chev spark faults

I bought a brand new chevrolet spark on the 21 November 2015.the radio was faulty they replaced the radio and said it's right I fetched the car and the radio was not right and they broke a brake in the console.they then took the car back and had it nearly a month.i collected the car and the the radio still was not right.they said they are getting a technician from GM on the 11th January 2016 I took my car in again and to find out there was no technician from GM.i then emailed them and the bank and GM SA stating I don't want the car as it's now been worked on 3 times and I have been **** to.i bought a brand new car they must replace it or we cancel the deal.they say I have to take that car they will not replace it or cancel the deal. PLEASE HELP ME.