Complain at game store polokwane limpopo

I bought my mom a dishwasher machine in game store the machine gave us a problem .we call game store and they send a technician who also mention that if he left then the machine keep on giving us problems we must take it back to the store we did just that now the problem is that the machine is still at the store they not giving us refunds they just keep the machine with them no communication with us Please help me with this metter