very unhappy with cell c

I have been having bad network Signal. Since 2010. And case after case was opened and all u ppl say is try to put ur sim in a outher I do that it's the same problem ten u ppl say to try a sim swap did. It and yet it's the same problem. My network gos down 247 my web is very slow. And today a lady phones me saying Tey did update the power by the tower I'm getting my network form bt yet I'm stll having the problem