ANGRY AND FRUSTRATED

Upgraded a contract and suddenly cant call or receive calls although I have over 800 minutes to any network. Customer Care puts me throught to Technical but the call is cut off - meaning i must go through entire process of security questions etc etc again! No one can explain to me why this is as everything seems fine on the system. Business lost due to inability to call or receive calls. ANGRY and FRUSTRATED! Technical dept does not answer - call is dropped after a while.