Blacklisted for faulty line

Our line has been faulty since the end of January 2017. We have reported this more than once, but to no avail. However, I was contacted by the billing department due to non-payment, this after I contacted them to say that I am not paying for a service not received. I was told not to worry my account will be placed under protection until the fault has been cleared. Almost a year later and I am informed that I have been blacklisted by Telkom. I have tried contacting via website since I do not have a landline, but also a waste of my time.