Damaged cellphone

Good day,<br> <br> My brother brought a Samsung Pocket on the 17/07/2015 and as he was tried to put his sim card into the phone, whilst being at the store, the phone repeatedly switched on and off. They sent it for repairs? Why are they sending a phone just brought at the store for repairs? It has been two months and nobody can answer him on the status of his phone. This is unacceptable, a phone that has a defect, more so when tested in store, should be replaced, no questions asked. This matter needs to be resolved as the phone was paid for, yet, no phone can be used.