Poor service from Internet provider

I have been struggling with my internet for more than a year, 3 people from the company have visited my house, 2 x I had to pay for and 1 x was for free,but they could not repair as the main problem is the internet tower, they have also promised to upgrade the tower for more than a year, but i still pay my installment every month but i do not get the same service with my internet only working 10% of the time. Numerous emails where send to them but no response, just automated ticket numbers.