My question involves an auto loan or repossession in the State of: Colorado

I had a car that was repossessed in the state of colorado back in 2000 after was all said and done the balance ended up being around 17000.00. I of course could never pay it and it has since been removed from all three credit bureaus and I checked for judgements and there are none listed either.

Well last week to my surprise I recieved a phone call from an agent regarding this debt I advised that I did not owe it as it is past the statue of limitations and hung up the phone. They called 3 more times in the next five minutes and I kept telling them that I did not owe the acct. I then sent the following letter via certified letter with confirmation of signature...



To Whom It May Concern:

In accordance with the Fair Debt Collection Practices Act, I am writing to notify you to cease further communication with me regarding a debt you allege I owe.
If you continue to contact me in violation of the law I will pursue all legal remedies allowed by Washington and Federal law
I am also writing to inform you that I dispute the alleged account with Bellco. I do not owe the amount alleged as it is outside the statue of limitations.
I have reported XXXX to the FTC regarding 3 calls made to my phone within 5 minutes of each other; this is harassment especially after I informed the agent to not call me at work.
This letter does NOT acknowledge that I owe any monies to you

So to make a long story short they sent me a letter today stating that if the 17000.00 is not paid in the next ten days they will then make a decision that may include legal action, without further notice made to me....

Can they do this? I thought I was out of the statue of limitations? Does my letter cover my basis or should I do something else? Does it matter that I live in washington now? I hope someone can help me as it is a very large amount of money.