I NEED HELP PLEASE !!!!!

Hi

I bought a hoover board from Tevo last year November. rom the day I received their product it only gave me problems . I paid R5000 for this product . I bought it the end of November 2018 . Two weeks thereafter I took it back as it did not want to charge . I was them told that they will sort this out in a week , it took them 3 weeks . I was then contacted and informed that the product was fixed I must collect it . I went to collect it and the next day we wanted to use it was never fixed .I then drove back to their offices and was promised that they will sort it out . A week thereafter I was told to collect a replacement which I did . The day after I collected it my son wanted to use it and low and behold it had the same Problem . I then called in and was told I need to bring it back to their offices , which I did . I was again given a replacement , but also had to wait another week . I collected the replacement as they couldn't find the fault on the 2nd one as I didn't want to charge . My son has 2 weeks to play with the 3rd replacement and then it gave the same problem , didn't want to charge .

I REALLY do not know what to do anymore as this people is just not solving my query and it feels whenever I call I am a nuisance . Can some PLEASE help