Payday loan harassment in TX. Please Help!

I had 2 payday loans from Liberty Group LLC and GTI Holdings. Are these legal in TX? A company saying their name is Metro bought these and is harassing me and my extended family. They have called my dad, my father in law, my husbands aunt and a random employee at my company. The messages say they are pressing charges against me and need to locate me. I called and they have my work location and home address. They said they have a locator that is searching for me and calling everyone and they can't stop it unless I pay them. They also said the locator will give me papers that I have to take to court that will show my ip address for taking out the loan. I asked for their mailing address and fax # to send them a cease letter on contacting third parties and they won't give it to me and I can't find info on them online. Please help.