Poor LTE signal, poor coverage

I have been a loyal customer of Telkom for many many years. I have a LTE contract with them. Two years ago I moved to Midrand where the internet signal is very poor. We managed to get some signal using a booster antenna and some days we even got decent download speed. However recently we cannot get speed higher than 0.5. Why is there no coverage where I live? It is not as if Midrand is in the middle of nowhere! I was hoping that Telkom would increase their coverage in the past 2 years but that has not happened. There are many towers in the area and we even have a tower on our property! Why do they not use the towers and give their customers better service?