harrassed by sanceda n their staff

it started in oct 2013 when isabela called claiming that i owed money to kagisano. So i asked her for documents of contract and proof of me owing. She said she will send it but sent me a statement of interest from 2009 and ntn else from then i kept getting threathenin smses. I called spoke to cedric mduduzi n few others n even spoke to selina dube the supervisor who promised me da contract n did nothing nor responded to my mails but today i get an sms threathing legal action on.31st march if i dnt pay. What is going on with this company. they operate against laws. they harassing me continiously and havent still showed me proof of what i owe...i feel like reporting them to the debt counsel. Can someone assist