Unwillingness to exchange

I bought a Ryobi petrol trimmer from them October 2019, it was taken back in January 2020 due to being faulty. I got it back and 2 months later took it back again for the same problem. It was sent to their local fixer upper guy and I was contacted to pay an amount of R 287.00 for repairs or cleaning. This is for a machine that is till under guarantee. I spoke to a gentleman or manager at Makro returns and I said to him that I do not want the machine anymore as I cannot purchase something just to bring it back every 2 months for repairs. I would rather then purchase an electric model. I spoke to Ryobi Midrand to a Mustafa who isndtructed me that the machine needs to be serviced every 50 hours of use. The machine has not even done 2 hours of work. The feedback it seems from Makro and Ryobi is that once an item is purchased and we have our money all excuses will be used not to assist in the repair or exchange of their it seems cheaply made product. I hope this reaches the correct people and gets the necessary attention. Social media and my persistance and determination in this matter will go far. My ***.