***** - charging me for a service I am not getting

I have been complaining to Telkom for more than two years about my ADSL line not working properly. <br> <br> Telkom tests it and says it's fine when it clearly isn't. I have done numerous speed tests (as they asked me to) and it is obvious that it's not working properly, yet they keep charging me. <br> <br> I have sent dozens of messages through their Facebook page and have been promised on numerous occasions that someone from management will contact me to resolve the issue. They have now been stringing me along on Facebook for months, without a single contact from anyone at the company at all. Basically, they've just been lying to me there. <br> <br> Prior to the Facebook messages I tried calling them. The first time I held for 40 minutes and logged the complaint. The following week I received a message and about 20 identical e-mails saying the problem had been resolved - it had not. I have now done this several times with the same result each time. Often you hold for ages and then simply get cut off. <br> <br> What's the next step? Do I have to actually lay ***** charges against the the company to get the service I am paying for?