Bad service regarding cell phone

On 6 June 2017 i bought my grandfather the samsung J1 from Ackermans Mall of the South. Hardly 2 months later the phone starts giving him problems. Last week sometime i took the phone back and was dealt with in such a disgusting manner by the branch manager. He in so many words told me that since i do not have the box he will put the phone in a plastic bag and if it comes back broken it is not his problem. He goes further and tells me to take the phone to MTN myself as if i bought the phone in an MTN shop right? Ok, fine and well, however when i bought the phone i was told that within 7 days if the phone is returned it must be returned with its original packaging. Not even the till slip mentions that the 24 month warranty needs for the phone to be in its original packaging. Excuse me for not holding my 75 year old granfather hostage for having thrown the box away.This phone is 2 months old i expect Ackermans to have it either fixed or give me my money bac****!