Highly dissatisfied and disappointed with poor customer service

It is with great disappointment and dissatisfaction that I write this review. For the past 3 days have I tried to speak with a supervisor on duty to discuss a concern on my account but to to no avail have I been successful. I was promised a call back but for some reason or the other no supervisor deemed it important to call me back. I understand that you have limited staff on duty but that does not account for your poor customer service. Do you not deem customers important enough to adhere to call back requests?