LTE a joke

I subscribed to a Telkom LTE package after having used their wireless internet for many years, with a very good signal and very good speed. I tested the LTE service first and got good speeds of around 20Mbps. Got the service, all went well for about three months, when suddenly, since last week, speeds dropped to less than 1 Mbps. Mostly around 0.3 to 0.6Mbps. A joke. I am paying for a full LTE service, I am getting less than dial up! I submitted a complaint (reference number ***9) last week, the agent at first acted like it was my own fault, as if I were being throttled for using too much data, but when she checked she realised I haven't even used half my allocated data. I get the same non-speeds on three different devices when at home. They all get a full Telkom LTE signal, yet no speed whatsoever. In different locations I do get the LTE speeds. So clearly a tower problem and nothing is being done, while I am losing my data. Now I am stuck with an expensive service that does not work. Seems like this LTE service is all talk but no action.