Damaged Cellphone

My father bought a Vodacom cellphone from Ackermans in August on the 26th, last year. The cellphone had issues, in October, as it was switching off. The phone had no damages or whatsoever done by my father, we took the cellphone back. Since October, my father has no cellphone. He has spoken to the branch manager as well *****ba from the Signet mall who has been nothing but completely useless and arrogant, promising my father phone calls and she never calls. They gave my father the cellphone in the same state it was in, he refused to take it. I want Ackermans to refund my father the money for the cellphone, we have slips and everything, and they can sort out the issue with Vodacom. WE WANT A NEW CELLPHONE OR OUR MONEY BACK..