I received summons of continuing garnishment in the mail from a collection agency who bought a debt I owed to Washington mutual. I was severed a summons almost a year ago and answered the court and sent a copy of my answer to the collection agency within the time allowed. I choose to settle with the collections company and make monthly payments. I could no make payments because I longer afford them. On this document they have my job payroll info. It is signed (stamped) and has a vague stamp. I checked the case # with the county court and it seems they served the company that handles payroll for my job. I have tried to contact the company on several occasions answered their automated calls just for the phone to ring out and hang up. I have left messages with no return calls. I also have a settlement letter from them that stated I had until 3/30/2011 to settle but the garnishment was filed 3/28/2011 @11:58am. Is there a way to fight this?

It sounds like you did settle with them and then defaulted on the settlement agreement. If you were served properly, signed a settlement agreement, and then didn't pay it as agreed, they are well within their rights.