Consumer Redressal

I have an internet connection of You Broadband company at Ahmedabad. I''m using it since last 6 months and just renewed my service pack for another 4 months. Since I''ve renewed my service pack, internet connection is down. They have replaced Switch(device) which is common in our building for all connections but still there is no luck. They are not giving any satisfactory answer about when this problem will resolve. They are not even picking the call. This problem continues since last 15 days. Please help asap.