Hopless Cell C Fibre

We installed Fibre to our home with Greencom. Last year they were bought out by Cell C. Now we have terrible service in every way. We pay for 50MG but get about 15 download and 4 upload. I have complained a number of times and NEVER had a call back. When I call I can be on hold for up to 30min. Can't use fibre for what I pay for. Hopeless Fibre and insulting service. My ref include ********** ********** 40 (last month) and 180 ********** 5206 82 (this month).