in the old days it used to take up to 48 hours but sometimes it is instantaneous. I would try again tomorrow morning and if it hasn't come through I would give them a ring and someone can do it immediately over the phone. You can tell whether it has gone through or not regardless of a speed test result by looking at your provisioned speed in the shub's config. This is the config for 350mbits, 400 down and 22 up:
You might find it reboots overnight and downloads the new config. If not, try a manual reboot tomorrow morning pulling the power cable out and putting it back in and if it doesn't come down then make a phone call.