Harassment

I got a call today at home from a man stating he was a process server for Collin County DA's Office and he is with the Sheriff's office and needed to come serve a warrant on me.  I was shocked and asked why?  He stated do you live ....are you still at this address are you now at this address and I stated who are you?  He again, stated he was from the county going to serve court papers on me today. He gave me a toll free number for what he stated was the county's office which is 1 866.872.6116 gave me a case no. which he called a Cause No. 008307-TX. I called the number was transferred to a Mr. Fisher's office who stated that law suite in the amount of $6,214.24 was filed in Collin Co., Tx and that warrant was out for me.  He then after back and forth said let me get more information from my secretary and state this was for an outstanding debt in from Capital One a credit card that I obtained several years back and had disputes over interest charges etc.  He stated that if I did not want to go to court or jail that I could pay $1,951.00 in full by end of business today and this matter could be cleared up.  I explained that I recently lost my job etc.  Anyway, he stated that I needed to call him back by EOB today or they will serve the papers.  Ok, so that was a heads up for me.  I called the DA's office nothing is filed on me as of today, after searching PMG it is clear that they do not practice best practices for collections and have been in trouble for this before back in 2004.  I need someone to give me advise. I want to pay off my debt, I don't want this type of collections to continue this upset me, made my blood pressure raise, this type of collections are not the right thing to do.  Had they called and ask to make arrangements or give me an opportunity to clear the matter, rather then threaten me by taken legal action, or harassment stating they are sending a sheriff over today.  This is wrong, bad business, and should not continue this company is bad news.