Stressed from collection agency/payday loans

I am in the state of Texas. I took out some payday loans and my son lost his job after doing so, which he helped me financially. A company named Metro had another number threaten me with a summons for fraud and also call my sister. She told me it would be in my best interest to call 855-683-2089 immediately. If not papers would be served on me for fraud and closing my account and not paying. I did call because I was scared. I gave them a loadable card. The amount I consented to is extremely too high for me now that my son has no job. I called them today for a fax and the lady that answered wouldnt give me a fax number. Told me goodluck when I told her what I was trying to reduce my payments. Said I had to talk to someone. I'm at work and don't like being harassed. What can they do to me for not having the amount they told me on the card?