Any body heard of National Debt Adjusters

received a call and a letter from Debt collector called National Credit Adjusters in Hutchinson, Kansas. They said I owe money on my master card, they said the will put a lien on my house and car and call my employer to garnish my paycheck. I offered to make monthly payments by sending a money order. They refused they want me to give them my bank account and routing number and they will withdraw the money. I refused to give them my bank account, the person on the other line got upset and said they will see me in court. I was willing to work out a monthly payment by sending a money order, I haven't heard from them again for about two weeks now. I am really worried that they will sue and put a lien on my house. The amount was not accurate, so I sent them a Validation Letter by certified mail. I don't want to give them my bank account. Any body heard of them, I need your advice.
Thanks