don't care attitude

on the 26th of May 2023 I called Montana batteries since my car needed a new battery. my car it’s a Mercedes Benz C250 Bluetec. indeed they've answered my call and confirm that they do have a battery. on the 27th of may 2023 I drove my car from Mpumalanga to their dealer just to buy and install a new battery for me. indeed at around 11h40 I've arrived there. they're technician then started to remove my original battery from the car that came drivable and put their Willard battery in my car. suddenly the car didn't start at all. n remember I can we a drivable car that now is no longer want to start the engine. they've tried to diagnose it with their machine. still the car didn't start. then I said to them their rather remove their new battery and put back my old battery and they did that but the car did not start. then at around 12h45 they started to tell me that they're closing at 13h00 I should call my insurance to come and assist me. I thought their joking and indeed they left me IN front of their business and close their shop. by that time I don't know anyone from Gauteng because I'm from Mpumalanga. then at around 16h12 I called their numbers that was on the notice board. the person who answered was LEON he said is aware with the car and these nothing he can do to assist me. that was a don't care attitude from them. at around 17h30 I decided to call Mercedes 24/7 luckily they've sent their technician to come and check the car. the technician told me that the car needs to go to their nearest Mercedes Benz workshop. I did left the car to Mercedes Benz work shop since I had no choice. who should pay all the costs?