Slow internet

When i started using rain it was fine since last year november ive been contacting rain support about slow network services im on the 24/7 R479 unlimited month to month. When i call support they tell me about there is to many people connected to the tower in your area . I asked them can they connect me to a new tower they said yes and their network technician Micheal will be in contact with me ....story short why is rain not sorting out the network speed issue we are paying for internet services we pay in full why can't rain.co.za not deliver