Poor service at Tibani Ackermans

I bought a cellphone hisense in ackerman's jhb cbd for my brother in Polokwane. After 3 weeks of using this phone my brother then informed me that the buttons are freezing and I advised him to take it to the nearby ackerman's store which is in Tibani mall for repairs. The lady at customer service told my brother she wont be able to book the phone for repairs as it is incomplete. She said it doesn't have the back cover which I didn't get in the box. I went to Ackermans in jhb to confirm if the phone comes with a back cover as I didn't get it. Godfrey and Beauty spoke to the lady and confirmed that the phone doesn't have back cover. The lady then told me she still wont be able to book it for repairs as they dont have the code or something. She said I must book it where I bought it. I'm traumatized of how ackerman's operates. I mean they are one but the nearest store is unable to assist me. Now I must go back to Limpopo take the phone to fix it in jhb. How crazy is that!!!