Thompson and Associates/Summit Group LLC

I need some advice. I received a call from a Ted at Thompson and Associates and left #1-888-688-2977. He left voicemail and i did not return his call. He called this morning and i happen to answer. He said he represented Summit Group LLC. THat i took a payday loan out and its been years, (he didn't specify how long) and that they had been sending letters and phoning and they have not heard back. I haven't received and calls or letters to my home. He kept saying he needed to confirm the last 4 of my SS# but i didn't want to, he got rude and then said there is a lawsuit that is going to be pursued and i would be served at work. I don't know if this is true or not, but i wonder if anyone else has dealt with this company before. I am in Texas and unsure if they would actually pursue legal action against me. He told me well i wouldn't want to be embarrassed if they served me at work would i? I said no but i don't know what this is, he said he already told me and that he needed me to confirm my social, i would not. Any ideas anyone?