Telkom mobile warranty problem

I took out a contract with them in July 2019. I chose a Samsung A70 headset. My phone fell and cracked a bit at the bottom. It never stopped working. I even put a screen protector on the crack. Unfortunately on the 20th of January 2020, my headset screen couldn't show calls and messages. The headset would ring but the screen was dark, I couldn't answer the calls. Messages would ring, but the screen was dark. Knowing that my headset was still under warranty, I took it back to Telkom. They booked it in for fixing, but 3days down the line, they sent me a message saying I must pay R5000+ for the phone to be fixed. I questioned that because the phone was still under warranty. They told me if the damage is physical, the warranty is deemed void. I told them I can't pay so much for a fine that is under warranty. The crack had been there for some time, but the phone was working. I was told to pay R189+ as phone assessment fee. My problem is , I must now pay monthly subscription for a headset that is not working. Please help me .