Internet speed slow

I work from home for a international company and recently everyday from 8pm I have internet issues, when I check the SA speed its fine but when I change the server to US the speed is low, Why I am I paying R800 if I will always have internet issues. This is affecting me at work. I need help asap, what makes it so frustrating is that unfortunately I can only send a whatsapp and all the time the next day I get a response saying there was an issue in your area.