Hisense u40

I visited one of your stores at edenvale van riebeeck mall (akermans) and did a laybye on clothes and a phone hisense u40 the cashier was thuli, after few days i got my phone it started giving me problems, i went to the store as i am not fami**** with the new smartphone to help me, they failed to assist me not only once but three times, unfortunately i didn't keep my slip yet the phone is seriously giving problems and they getting worse day in day out i would to get my money back.