I bought a microwave online which was not delivered and I have been calling with no assistance from the Agents and I was told to log a request for return which I did but until today no refund

I bought a microwave online which was not delivered and I have been calling with no assistance from the Agents and I was told to log a request for return which I did but until today no refund. The consultant are not assisting and email not responded and I have run out of airtime to call since they put me on hold saying they are escalating until I run out of airtime and they will not contact you back I need help with a refund