How long does it take for a speed upgrade to take effect? I upgraded to gigabit service more than 24 hours ago, and I still haven't seen a speed increase from my previous plan. I've reset/restarted my modem several times.
Unless there are special circumstances (ex: a new modem or gateway is need to handle faster speed) the change should take effect as soon as your modem or gateway is rebooted and before the chat or phone call ends. You should probably check back with them so see what the problem is.