What is the procedure for a seller to cancel escrow?

I am currenly in Escrow, trying to sell my home. However, I have a horrible agent and the buyers are not taking any action. It's been a week and a half and nothing has happend (we're in a 20 day escrow). We don't even have a prequal letter or anything... I already signed a "Buyer's to Perfom" letter giving the buyers 72 hours to remove the contingencies. However, my horrible agent is telling me that it doesn't matter and these buyers could have us in Escrow as long as they want. I need help, my husband and I are sick of it all and want to cancel Escrow and not even sell our home anymore because of all the headaches. Someone please help us. We need to go above our agent's head and try to cancel escrow!! Is there any way for this to happen and if so, what's the procedure?