can you be incarcerated for 30 days for non full payment of a debt

There is no longer any such thing as debtor's prison.  You cannot go to jail for failure to pay a debt, unless it is child support, but even then you would have the opportunity in court to pay it before you are sent to jail.  Even if the debt you owe is due to criminal activity, such as theft or embezzlement, this would still be a highly unusual way for it to be handled.  More likely, the sheriff or police would simply come arrest and charge you.  It sounds like you have been the victim of highly unscrupulous debt collectors or scam artists.  If they call again, you should try to get additional information from them and have them send you something in writing verifying the information. This answer is given in accordance with the laws of Virginia and may not be applicable in any other state.  It should not be construed as legal advice, as that would require a more thorough analysis of all of the facts involved in a specific case.  If you need further information or assistance, please feel free to contact my office for a consultation. Case results depend upon a variety of factors unique to each case. Case results do not guarantee or predict a similar result in any future case.