Complained against Telkom

I want to lodge a complaint regarding the above, in March 2024 I took my Samsung Z Fold 3 to Telkom offices to be repaired, my phone was in an excellent condition when I gave it to the officer, one side of my screen was not working, it was then send to the technicians I was still under the impression that this phone of mine was still under guarantee, apparently not so the technicians send me a quote of R18000 for it to be repaired I refused to pay this amount for it to be fixed. I went on 23 September 2024 to pick up my phone from the Telkom offices, when I arrived back home I took out my phone the screen was not put back together as well as my touch settings was not working and when I open my double screen it was totally black, my phone came back in a worse condition with nothing working on my phone. I feel this was not right from the start to expect me to pay that amount of money for my phone to be fixed, this is a very expensive phone that I had for 3 years. I need to get my phone back in the condition that it was, I have been a loyal customer of Telkom for many years I really expected more from you.