Bad attitude and Black Mail

I purchased a used car from Aurina Ford, on the 04/05/2018, they brought me my new vehicle and took my trade in vehicle to there stand... Tuesday 08/05/2018 I was formally informed via E-mail that there is a problem with the trade in and that they want there Mazda back and that they are coming to collect my Mazda and bring back my VW polo after I signed contract with Wesbank on the new vehicle... so the complaint is that the used car Manager is so rude over the phone that I had to tell him anything he want to say he is more then welcome to say to me via e-mail and not over the phone. then also they gave me a call this morning where i do have a recording of it telling my that the sales person that sold me the vehicle is been fired because of this transaction I call that black mail. So this is poor service and I think that this is a dishonest way of selling vehicle and that they can not provide on there website a place for trade in evaluations if they can not keep up with that fact that they give a price and then the price is different after giving delivery and taking the trade in vehicle.