BestDrive harties

Nearly a year ago I bought a battery by them they installed the battery after about 8 months my car started locking and unlocking itself. Saturday afternoon I heard a popping sound and my car didn’t wanted to start. I took my car to get checked out by a auto electrician and he found my car battery is below voltage and it shifted in out of place. I took my car back to best drive and said that the battery is faulty and has shifted. Where they said they need to charge it and test it but in the meantime I need to buy a new battery. Then if they find fault with my battery they will replace it. The technician already said that there is damage to the outside of the battery housing and that the warranty is nil and void. After I explained that the battery they fitted is not the correct battery. He jumped started my car but couldn’t even connect the terminals of the jumper cables correctly and caused a short circuit. The first guy installed the incorrect battery and second guy couldn’t jumpstart a vehicle correctly still they don’t want to listen to my complaint and help resolve it with out me buying a new battery.