Bad service

My father bought a fridge from the above named store and it worked for a year and he called them to notify them that is no working then the send someone to fix as it was still on warranty /qarantie and he fixed it and worked for a month and stopped again it was reported again and they took it this time and claim it was tempered with they can't fix it wherels their are one who did that, we asked them the photo of the the first technician they couldint provide