Metro Car Sales ********** behaviour

I tried to sell my car to metro car sales and they say i should rather sell it provately and have them assist with finance applications. I found a buyer and they sent their documents to the dealership for finance application and got approved. The sales manager then told them to not buy my car and buy one of theirs instead. The buyer called and told me this ********* behaviour from the Metro Car Sales Manager Mr Elvis Naidoo. I went to the dealership to finalise the deal and Mr Naidoo started telling me they would add extra charges to the sale and vat had to be paid and other suspicious things that they never mentioned before the deal came to their table. I ended up cancelling the deal because of the shady behaviour. Be careful when dealing with Metro Car Sales.