FAULTY CAR SOLD

On 1 February 2016, I purchased a Citro?n C4 from Bryanston executive cars. Very excited this is my first vehicle in my name baring in mind I'm a single mother of 2 girls. Upon collection I filled my car up only to find the petrol tank was leaking. The car was sent back to the dealer in respect of this further the car started cutting out only to find out the ECU and ignition was faulty they refused to take responsibility till it was taken in for a second opinion. I got the vehicle back a week ago and yet again the problem they claimed to have fixed has not been fixed and I'm stranded with a broken down vehicle with no other forms of transport. You have sold be a faulty unreliable vehicle and the service has been absolutely shocking. I WANT THIS DEAL CANCELLED.