PNC Bank complaint: No honor

I signed up for a business credit card with the understanding that if I spent 3000$ in three months I would get a $500 dollar credit. As I was spending, my credit card got declined for a number of days as I was in the last few days of my 90 day period and BEFORE I reached the $3000 mark. I spent 2817.50 the remaining 182.50 I COULD NOT CHARGE BECAUSE THE COMPANY DECLINED MY USE OF THE CARD. When I spoke to their representative Amanda Smith she said that none of the above mattered because I did not meet my part of the agreement. HOW IS THAT EVEN POSSIBLE IF NOT FOR THE COMPANY BEING DISHONORABLE. I have been on hold for unimaginably long periods of time trying to talk to a supervisor and I have left messages for the representative at the branch I go to in Tucson Arizona who signed me up for the credit card offer and no return calls. I have not yet been able to cancel my credit card because I can to get anyone on the line!! I want to change banks and plan to after the holidays. PNC is not the kind of bank I want to do business with!