Makro / Trimtech grass cutter

I bought a grass trimmer from Makro. The brand is Trimtech. It went fault the very first time I used it. I took it back to Makro. They took it and said they will send it for assessment. They updated me that it was received. Makro again told me that I can collect it it's ready. The second time it went faulty I didnt want it anymore for this reason of going back and forth but the lady who was assisting me said I have to bring it four times before they can refund me. The third time it went faulty and I took it back, the same process followed but when they gave it to me they didnt fic it and didn't even notify me. I went home used it it never came on. When I took it back this forth time thry told me that the part that is faulty was not warranted. I tried to reason with them (the Assistant and the Manager) but the Manager who was helping me refused refuding me saying Trimtech will not refund her.