Don't be afraid to keep calling back when you don't get resolution of your problem. The capabilities of each operator are vary varied and some are more willing to help than others. It takes persistance but if you do not get anywhere hang up and call back, you will get a different person.
Also a hint that you are considering cancelling your service will often work wonders, especially if you can get put through to client retention.
But keep a record of each contact, date time and the name of the person you spoke to and what they said.
But don't blame your operator for everything, they can only contol thier part of the network and the internet is a big wild place.