Cellphone 4 weeks in repairs and still no phone

I bought a Mint Fox cellphone from Pep Newton Park, Port Elizabeth on 25 Oct 2017. On 3 Nov 2017 I took the cellphone back as it didn't want to charge and must always be connected in a charger. It was8 days after my purchase which they said it will have to go for repairs and will be fixed within 3-4 weeks.

I went to the store today 1 Dec 2017 (4 weeks has passed), I am being told MTN will send a new phone but they cannot tell me when and they must phone MTN on Monday to confirm.

I then told the lady named Siphokazi, should I not hear anything I will come in next Friday.

I am very unhappy regarding the poor service, which now means I will be without a phone for 5weeks. I need this sorted ASAP or I want my money back!