bought a BMW x1 and they sold me plugged runflats!

I am very unhappy with the service I have recieved from BMW! I recently bought a BMW preowned X1 from fors****s tygervalley. when I found out how expensive the run flats were I specifically asked if there was anything I should know about them and all the sales guy said was that they are fine and have +/- 75% wear left on them. 2.2 months later I get a warning sign and take it to be checked at Autoquip by a man named ALI and he shows me that there has been a plug in the tyre the whole time and that this was done as the man who owned the car before knew there was a puncture and did a quick patch up job just to sell. When we called the sales man at Fors****s (shaun) his answer was that they would not help as i only noticed this after 2 months. I am FURIOUS! I bought from BMW to ensure that i never had issues like this. It cost me R3650.00, it is the principal of the matter that really upsets me the most.<br> I have since spoken to BMW South Africa who have spoken to them and they say I was lying as a quality check was done prior to me buying the car.I have a letter from Ali at autoquip who did the assessment. How can they say I am lying? this is outrageous!