Cell C Fibre FRUSTRATION!

I am SO FRUSTRATED at the service of CellC Fibre, I just don't know what to do about any more! I have been trying to get a technician out to my house to test and fix my system for the last 2+ months. I am not getting the reach that I was promised,nor am I getting the "guaranteed" up/down speeds that was promised. I have phoned over and over again & have emailed them too, to no avail. What must a person do too get some action??? Paying for a 100/100 fibre line is not cheap, so surely I can expect some courtesy? The agent that signed up the deal was really great until the deal was signed, now he is prominent in his absence, too. Come on Cell C, you can do better!