Consumer Tax Relief Fraudulant and deceptive Nationwide

I had notice from the IRS that said they were going to start garnishing my pay, I didn't know what to do. I was listening to the radio and I heard about a company(Consumer Tax Relief) that was advertising that they could help people who owed money to the IRS. I gave them a call and they said they would help but I would have to pay $2000 first. I agreed and they started me on a payment plan, paying $250 every payday( 2 wks). But after I had made about 3 payments on my payment plan, Tha IRS started garnishing my pay. Thay were taking about 75% of my take home pay. Needless to say, I couldn't continue to pay Consumer Tax Relief and still pay my bills and feed my kids. I am a single dad and I still have 2 boys that still live at home with me. When Consumer Tax Relief called me and asked why I hadn't been making my payments, I told them the IRS had started garnishing my pay and I couldn't afford to make payments until the IRS was finished garnishing my pay.

I asked them what they had done on my case to help me with the IRS's garnishment of my pay. They said they couldn't help me until I finished with my payment plan. I told them I wouldn't be able to have any extra money until the IRS was done, by which time I would not need thier services anymore. Somehow they could not see the logic to that. So after the garnishment of my pay ended they started calling me again. I told them I didn't need thier services anymore, though they didn't do anything in the first place. But, they still say I still owe them the balance of the payment plan. How do I convince them that I don't owe them anything since they didn't do anything to help me?