Linteg Fibre bad customer service and resolution time

I am paying for a fibre line with speed 100mbps up/down but am only getting speeds of between 20 to 40 mbps i call was logged and even after following up on the call and ticket no resolution even after 3 days sorry part is that its not the first time that this issue has come up previous time it toke more then 15 calls to have the issue resolved also in the past had days whereby there was up to 4 days complete black out on the fibre but still full months subscription was taken