A.C.S Threat to send warrents for me and my sister who's disabled n have no checking account. calling my job, my family Internet

They call endlessly and threating me about sending out someone  to arrest me for bad checks, fraud, and closing my accounts.Now they are trying to do the same to my sister who's disabled and have not had a checking account for 5 years or more. They're calling my family my job asking how to get to me to arrest me and also changing there numbers every once in a while.When asked for there address they told me they dont leave paper trails so you can't find them and just demand that I give them my account number to them and start yelling band scream and curseing at me. Also can't write a check to pay my bills because they put me on the telecheck system for check fraud. These people needs to be stopped and run out of business because they are destroying people's name and credit.