Weed Man

Today I received a 10 day notification advising that I owed 473.94 in late payment charges for an issue that was resolved in 2009.
I hired weed man back in 2006/7 and prior and was happy with the results and paid for the service. Back in 2008 I don't know what happened, I hear they went green and the product they used wasn't applied properly, in any case my grass never looked worse, the weeds were out of control. In early 2009 I called with my concerns and dissatisfaction and I refused to pay for the service of 2008. During my numerous phone calls I was made to beleive this was resolved with upper management. Today after all these years I am receiving a bill for $695.95 of which $473.94 is for late payment. I called to resolve with Marchel who represented herself as the acting manager and person in charge. I noticed the bill showed I was being charged for two applications in May 2009 this was after I had already asked weed man not to continue service and that I was not willing to pay for the applications of 2008. I was willing to resolve this today with her and pay for the July 08 and Oct 08 fertilization but I refuse to pay for the weed control, she flat out refused and told me that I had to pay the full amount and that she would waive the late payment charge...this is a joke. If Steve reads this message I would appreciate a call back...I am extremely upset!