One Eight Technologies Private Limited - Issues with Internet Service is not being resolved

Nuron ISP is taking no initiative in fixing their internet speed, as I'm getting not even half the speed that I'm paying for. Their monitoring portal used to show the data consumption which they have stopped and they are not fixing it. All these even after multiple calls. They have also closed their complaints section on the portal and they never call back after a ticket is raised by phone either. The distribution centre at my place has done all they can, but the backend is not taking the slightest initiative to fix it rather than repeatedly performing the same diagnostic steps.