Grass trimmer

My experience with makro Woodmead is the worst experience ever in retail industry,I bought a grass trimmer from Woodmead makro in October 2017 and the trimmer came with a trimmer wire installed from factory and I only used the trimmer for a maximum of for times then it broke and upon returning it to the store I received a call two weeks later informing me that I over used the trimmer and the installed trim wire was incorrectly installed,to my surprise since i never touched the wire I called to query why I should be charged R+-400 for something that’s still under warranty let alone me touching the wire,i then asked to speak to the manager Aubrey hadebe who was very rude by not willing to listen to my complaint and hung up the phone on me,i then called head office which did listen to me but haven’t gotten back to me as promised since last week and now I’m stuck with no trimmer and no word from head office or makro Woodmead