Undermining service

About two months back I bought a Qdos power link at iStore the Glen mall, now the device has a problem, the connector is loose and the answer I'm getting is that they have never received a complaint for this device and refused to take the device of which it doesn't make sense because it's still under warranty. I was also told that they are waiting for authorisation but they never logged in a call for the device and I still have it with me, the logistics of going back and forth for a device that was promised cover when I purchased but when it disappoint the customer takes a fall.