Autohaus Centurion - the new McCarthy Standard?

I purchased a BMW 116 from Autohaus Mastercars in December the car stood for 10 days with a water issue. I got the car back and 2 later another problem surfaced. I contacted the dealer and was told to drive the car with the issue throuhg to them....they couldnt give me a loan vehcile and car had to be booked in on the 23rd with no guarrentee on the lenght of the visit. Seen as though i needed the car as it was recently purchased and they werent prepared to assist with a loan car and i wasnt prepared driving a broken vehicle with the risk of causing more damage i told the salesman i will get my mobile mechanic to assess and will forward the invoice. My mechanic who worked for BMW for 11 years and now has his own bussines who attends to my other vehicle amd is trustworthy came out. He plugged in his BMW software and diagnosed injector 2 as faulty. He also told me the oil is thick and dirty as was not replaced prior to delivery as promised. He got me the injector brought oil and a filter and invoived me R3500 all inclusive which is a *****. I paid and forwarded the invoice and now the DP at Autohaus refuses to refund me. So it is ok to lie about and oil service Selling a mastercar which went through apparently an intensive 80 point check with 2 different faults within 3 days the vehicle was in my possession. Not being prepared to assist with a loan vehicle and keep a family with holiday plans stranded and then after a specialist repared at absolute minimum still have the audacity to reject? I am sure this is not the McCarthy or Mastercar/VW standard??? I can ask mechanic to come and puy back the faulty injector and send it to VW autohaus to repair with them giving me an automatic courtesy vehiclw whilst its in for repairs......i can take the R3500 knock less the lie of oil change that was not done......it will cost them more to repair and they want to be funny????? I want to be refunded today still as i went out of my way to be helpful when yhe dealer felt zero for me Alternatively they can refund me on the followinh basis.....what BMW charge for the injector oil and oil filter plus diagnoses and labour shoukd me R3500 not be refunded today. I have been more than fair and reasonable towards them where they should have been towards me. No i experienced been **** to about the oil service (which is *****) and zero assistance for inconvenience.