Yup, the offline renewal is problematic. I would advise against it. I tried doing it this month and got the same error twice. Basically my link to the server was broken and i was stuck coz the renewal thing doesn't have any back/refresh button. Both times this happened after payment had been made from my card, on the first occasion, i didnt even note down the authorisation code consequently had a hard time convincing sify's renewal department that they had received the money. Second time over i was better prepared and on giving the call centre fellow the bank reference number, my account was credited that night itself.