ROCHESTER, N.Y. — Three months after a boxing event at the Blue Cross Arena failed to cover its expenses, promoters Clay Harris and Derrick Grambling say they are working to pay back everyone involved. The April boxing extravaganza didn’t just fail to turn a profit — it didn’t even cover expenses, leaving the promoters thousands of dollars in debt. Harris and Grambling have spent the past three months going over every detail of the failed event. What hurts more than the disappointment, the promoters say, are accusations that the fight was some get-rich-quick scheme. “This is a heavy, heavy, heavy, heavy, heavy weight on me.