No responsible person on duty to make decisions

Bought my daughter an iPhone 6 and a cellphone cover and screen protector. Prices on items and systems different. No manager or supervisor to override system. On the 2nd of January wanted to return the cover as we found it defective. Again no manager or supervisor to okay refund or replacement. We were told to return the 4th. On the 4th we again found no manager or supervisor. What now? Do we make a trip evertime hoping that we will find someone responsible on duty. The staff on duty's hands were tied. Really bad service. Great company and excellent products , but staff like this are this give good companies a bad name