We Buy Cars deceptive trade practice

Bought a car for my son at we Buy cards Midstream. They said that they need to replace 2 x tyres for it to be able to go thru roadworthy. I agreed. Now the problem comes in. They charged me for the tyres, added to my Finance, charged me for Bridgestone but fitted Autogrip budget tyres. I have taken it up with them, now they are spinning stories that the autogrip was on there and they fitted Bridgestone at the back. Such a bunch of nonsense, you fit new tyres in front and not at the back. I even send them photos and n video that clearly shows the autogrip is the new tyres and it was fitted in front. Which i got add the photos on here. To me that is deceptive trade practice and *****.