Bad service , No regard for POPIA act , no update or feedback

Went online , completed my details , received a phone call explained i have the car for a 4 days now i saw a new car at Reeds , received an offer of 45k , I then got a call from Chris the buyer, I explained to him i paid 50k for the car so he told must send proof of payment which i did, He then wanted a sales contract which i handed in to the registration department when i did the ,lic and registration and change of ownership , then he wanted me to get the previous owners contact details , Why do i need to do all this if your offer is just 45k , i whattsapp him to ask if they still going to buy the car , up until today i have not received any response from them , this is really bad service , Now that other car is sold !!! POPI ACT GUYS I CANNOT SHARE INFO ABOUT THE PREVIOUS OWNER WITHOUT HIS CONSENT !!! Very Bad service Chris