Sold a broken vehicle

I bought a vehicle from WeBuyCars Montague Gardens on 24 August 2022, and collected on 27 August 2022 so that I can do E-Hailing as I'm out of work. On the 9th of September 2022 it didn't want to start and after more than 45mins it finally started and I took it to for mechanical repairs thinking that it would be minor repairs. To my astonishment what needed to be repaired amounted to R24k as it was an engine damaged that had serious issues and had to stripped. I collected the vehicle after a week and drove it but then again there was an issue and that oil pump that needed to be replaced and that invoice is more than R5k. Currently I can't drive the car as the water is mixing with oil and needs to be fixed. I wrote on their Facebook page 28 October 2022 and got a phone call from their Customer Care Agent by the name of Shane Maboye seeking that I must send the invoices and take a picture of the current mileage on the vehicle. I did this on 31st October 2022 and on Friday 4th November 2022 got an email reply from Savannah Malherbe stating that WeBuyCars is not liable for any repairs/fixes on the vehicle. This very hurtful because I paid my last sent thinking that their vehicles are reliable as I need to make a living so that I can provide for my family. What I bought from WeBuyCars is more stress for me and I don't understand that they don't want to take responsibility as I furnished them with the invoices to indicate the repairs done on the vehicle. Why would they want invoices from the mechanic but they knew very well that they're not going to take responsibility? Why are they selling cars that they've not checked if they are fit to drive? I trusted them and now this... I can't believe that they taken my hard earned cash and not willing to assist.