direct readers guild company called saying i was being held accountable for an account i was unaware of. California

i was first contacted buy this company at work they just wanted to sell some magazines,i had never herd of them before,and figured sure why not, then i got my first bill and tried to set up a payment plan online like what all other companies do.

i couldn't find a single website all i found was complaints that the company was a scam, i started to get worried and tried to contact them but could not find any contact info.I finally got a call saying they had payed ahead around $900 and said that i could pay a little over $400.

i was also told i would never be contacted by them again if i payed the $400, then i started to get these calls on my cell phone, this was about 6 months latter i didn't know who it was so i didn't answer they didn't leave any messages finally i picked up. 

the woman started the conversation with the Direct Readers Guild is holding you responsible for $900,i told her it was already taken care of and asked her why she was calling me?

she asked if i had a finale statement stating it was payed off which i didn't but had a copy of the check that they used to take the money out of my account,but i was at work and couldn't look this up for her at the time. she started to give me an attitude and tried to get more money out of me the same way as before tried to say it might be another account,and if i didn't have the finale statement  it was going to go to collections,i have only been aware of one account. i ended the conversation and hung up the phone .

hollyms8406@yahoo.com,