Bad car sales experience!

I have bought a car from them in Kempton park . At 1st the service was good. As we struggle to get a car we like and trade in my i10 Huandai. The original sales person mess up by note keeping me in the loop as promised. Then some else helped me. In the meantime while I have signed the papers in the question asked (I have asked when will the new payment be debited. They said 1/9/18. ) Which was perfect just to found that they didn't do the full down payment on the I10 they have taken at the 16/7/18. Now I have received SMS from mfc to say there is a payment outstanding. And in the same time they cafe me a full explaination that they have paid everything in full and already received the natis on the i10. When I phone them to asked what is going on they only wanted to explain now to me ;who is liable for paying a car I no longer have. And earlier today the person in charge of account and finance department at Ginda motors said to me I have checked you do not owe any thing to mfc. And mfc seems to disagree. And now after I have the Baic 3weeks plus they wanted to explained. And after I have signed the1 St original sales contract;there is sundenly a new one the next day that needs to be signed whitout any explanation. And I were pressure to do so while I am constantly busy at work.