I want a refund

Bought Candy cellphone on the 6th of August this year, took it in on the 22 September because it wasn't charging any more. After two long months of enquiries I was called to the store where I was informed that I need to pay additional R600 so that HMR Networks can fix the phone. Firstly, I refuse to pay R600 since I bought the phone R800, it simply shows that Markham sold me a low quality product, Secondly, it took them over two months to inform me of the quote even after I made numerous enquiries, lastly, they couldn't bother spelling my surname correctly. I am utterly displeased with the service I am getting from these two companies as a result I refuse to engage further.