Pay day harassment

I had a loan with payday loan yes and cash jar, i had paid the principal on both, for payday loan yes i overpaid by $120 and cash jar by $25. I cancelled bank account and sent revoke letters. Payday loan yes called me today at work saying i owe $650 w/prinicipal and interest. I in the past advised through communication through email when they contacted me that i owe nothing as well as when i spoke over phone. I asked for their address and license #, they said i could find address on website but wouldn't verbally give it when i was speaking with them, i again asked since the lady was badgering me and telling me their laws apply and not mine in NJ, she then hung up on me. No address appears. I just want to be assured that no one has the right to come after me that what i'm saying to them is correct. I paid principal and despite their laws or their electronic agreement i signed, it is not valid no matter how many times they say it is. I just want to know how or when i can get them to stop contacting me at work and home. What can one individual do to at least shut these people down after the prinicipal of the loan was paid.