Undisclosed modification

I from Middelburg EC. I bought a 2019 Haval H6 on the 3rd August 2023 at Autoxtreme dealership in Pretoria. The sale person was Reghardt du Plessis a gentleman if I must say. I fetched it and drove it few weeks. Towards the end of August the car didn't want to start.I thought that the battery needed to be replaced.i went to buy a new battery to my surprise the battery wires have been modified and there's a inventor battery that was operating the car. was informed that this kind of battery is not used for the vehicles. I informed the salesman about this because this battery requires the car must be like a shark driven every day,if it stopped for a day it must be jumpstarted.Such that I must drive with jumpstarter cables. The sale person informed me today that they dealership is not prepared to repair the modification. My problem is that they didn't diclose to me the modification of the wires and the kind of battery that is operating the car. I feel that is unfair because that is something that should be disclosed to a client it has to do with an engine.I request your assistance. Clients must check the battery or engine when buying a car from such dealerships. From Unhappy client