Bad internet and Bad Bad Service

How do one start with service, well good for the first day and non existing for the rest of the year.

My internet is slow hanging or down for more than a few months. As for today down and no one's answers or the so called chat speed group no luck on both hanging on for the past 45min. Called yesterday day before and and like magic nothing. I was promised better support if I stayed as I wanted to cancel twice. I gave business to them but it was a mistake as these users have the same issue with speed and connection. I even upgraded to 100mb line. Received dedicated person a month ago to help, but this also did not pan out after a week. This company is full of excuses, they are ruthless with no support or commitment.