I made payment arrangements with a law firm back in October, 2014. They have since disbanded and are seeking payment in full. I have made all my payments according to the payment plan, they have cashed my checks & are still continuing to cash my checks. They have now filed a lawsuit demanding payment in full. I need to file my answer. I am not denying the debit. However, I am denying paying it in full since I have a payment arrangement prior to this. What do I use for my defense in my answer to the lawsuit?