worst internet service

Hi I have been having problem with my rain speed for 2 months now paying every month for service that I don't get. I called and sent mails to get this issue resolved but everytime they just tell me to follow the step or give them the sim number to send it to the relevant department and put the router close to the window how much closer does it need to be must it be one with the glass??? I'm don't with the step and all there stories I'm Feb up with rain its the worst internet service ever I get promoted everytime that it will get sorted but its not happening.