iStore Sandton Drive Damaged my iPhone.

After my phone was returned for a battery repair, I noticed my screen was damaged. I immediately brought it to the attention of the Sandton Drive Management. They called the technician back and he claimed the damage was preexisting as the device was booked in dark mode. This is a lie. The management tired to seek approval for a replacement but Core Management stated the same thing. The damage is clearly visible in dark mode and is getting worse. The damage was caused during assembling. The damage is located beneath the the glass on the LCD further indicating the the damage was caused during the assembly process. The iStore must either replace or refund the cost of repair for their negligence. Poor handling of my complaint. Poor workmanship. Poor level of professionalism.