Ackermans - New phone failty

I visited a Ackermans Store number 1918 Alice Kwantu Centre to return a phone I bought last week Friday, a phone I noticed it is unable to make calls due to a mic/ speaker problem. I confirmed it last night at took it in today, only to be told I won't be getting a new phone as per the terms, only to get ill treatment from their superior. I feel robbed, as a client I am so disappointed with this shop.