Refund or exchange denied

Bought a small phone,started to jave line on the screen,went to Ackerman's balfour Mall and was told we need to take the phone to repair and it might come back next year because you have to book but when i bought it was told that any problem within 7 days i must come back exchange or refund even the slip says so but today was told that i might be charged again for transporting that phone for repair,i regret it bad service from Ackerman's 🚮🚮