Damaged cellphone

Bought a cellphone at the store and it was faulty, took it back to the store and they promiesd to repair it as it was still under guarantee. And they said it was going to take two weeks for repairs and when i came back after three months the phone was still at the store no repairs done, and told me Scelo was on leave and that why it was still not repaired. Then they promised me they going to repair it and will come back to me within 3weeks but these still no feedback from them.