Legal Mediation Practice Threatening Jail time if not paid in one hour Jacksonville Florida

I just got a disturbing phone call earlier today, April 30, 2008, from Legal Mediation Practice of Florida. The man claiming to be an attorney represetting CashNetUSA, told me in so many words, that I would be put in jail for writing a bad check( electronically/post dated as well).

Only info he gave me was payment options. Either pay him with credit/debit card now, pay by Western Union or MoneyGram, or pay online to Moneygram.com.
Receive Code# 4716
Paid to: LMP
City and State= My city and state
Acct#=Case#08-677537

I am calling the local Clerk of courts tommorrow, to find out about the law. One website said that I should receive a letter first that they would file with Clerk of Courts, stating that I have only 7 to 15 days to pay in cash to them or judicial litegation would be started( Sheriff nokking at door in middle of night for my arrest)!

I have never received by mail any letter from CasnetUsa telling me what to pay or when. All I ever get is the same "this is an attempt to collect a debt......" e-mail once a month. I sent them an e-mail once, trying to set-up some reasonable payment arrangement. No answer!

Should I be worried of jail time??

Travis
Fort Myers, Florida
U.S.A.