[Resolved]  Sify Broadband — Connectivity issues

I have unlimited connection of 128 Kbps in day time and 256 Kbps in the night time. Whole day I am at the office but I keep downloading windows update and other things. Every night there is probelm at the gateway and this probelm has been there for more than two weeks. I have complaint to local office and there so called 24/7 call centre but there is no improvement. Once the engineer came but at that time the internet was working so he went back and the issue was mentioned as resolved.