Billed me after i did not renew my contract

I went to Virgin Mobile at Pavilion Durban to inform them i was not renewing my contract in Jan 2014. Few months later I received a summons from a Durban collecting agent stating i owed Virgin R754.00 Virgin did not cancel my contract and carried on billing me. Plus they billed me for invoices they did not send me. I emailed copies to my emails with Virgin to this agent who told me he had sent correspondence to Virgin and will revert .(July 2014). In or about Apr 2015 I started receiving SMS from a collecting agent in Jhb claiming i owed Virgin R754. Next SMS was R150 then R100. I forwarded correspondence to them with CC to Virgin. Plus an email to Virgin Mobile director. No reply from Virgin. Am still being harassed by collecting agent who has *********ed my email and tel number. When i email them its returned to me and when i phone them the call is cut off.<br> In my email to Virgin and collecting agent I have written that if they don't stop harassing me i will contact Virgin HO in the UK and Noseweek. Still no reply from Virgin!<br> All email correspondence detailing waht happened available for your perusal.<br>