Cell C cannot be trusted

I took my phone, still under warranty since it was purchased last November, for repairs at Cell C on March 29th. It's now May 10th, and after struggling to locate the phone, which I found unprofessional, I had to initiate contact for updates as they remained silent. Eventually, they located the phone and sent it for repairs.

The issue with the phone arose when, months after purchase, the battery began expanding, inevitably causing damage to the cover and other internal components. Cell C used this as grounds to nullify my warranty, alleging that I had tampered with the device by removing the cover.

Given my background in tech, I comprehend warranty regulations, and their accusation of human interference is absurd and arrogant. It's logical that if the battery expands, the cover will break. To use this as a basis to reject my claim is utterly unreasonable. I refuse to accept this outcome and demand they rectify the phone at no cost to me.