Superfast internet? Really?

After having had an LTE home office connection from Telkom for almost 18 months and having been very happy with the speed of the connection I was receiving (11 out of the potential 20Mbps), the connection has now dropped to below 1Mbps ( equivalent to a 3G connection). This means I can no longer use my home office as the speed is not sufficient.<br> I contacted the provided support number (081 180) and after being on hold for 9 minutes the call was dropped. How on earth am I supposed to use my data when I can't use it as intended or marketed. How am I suppose to raise this when my service provider won't hear me???