Poor customer service and billing

I cancelled a contact in July, the cancellation was accepted. I was sent sms 's and multiple emails to confirm the cancellation. That contract continued to get billed from August to December, l thought it was cancelled and thus never made use of the line. I called so many times and all that I'm told is "I will log a case and escalate". Now at the end of my current contract in February the bill has gone from R115 to over R500 on a contact that was cancelled due to payment rejection fees that I must incur because my matter is not getting solved.

I have sent a follow up email, I just get an automated response with a reference number. I was given a reference number when I sent in the query, now I got a new reference number on the email to follow up on a reference number logged a few months ago. Not even sure if my query is even being attended to. Utterly disappointed.