SCAN Class problems

I recently noticed our cellular modems are using much more data then they should be. I have already called into Tech Support and they could not resolve the issue. But our Scan Classes for Alarms every 7 minute polls, Overview 15 minute polls, and Setpoints 1 Hour polls are not working. I just tested a tag that is set for 900,000 milliseconds (15 minutes) and it updates the tag a few seconds after i change its state. I just recently took back over our SCADA projects again so I am not sure how long this has been going on, but I know when I was involved with it on a day to day basis the Scan classes had worked for years just fine and would only update the tag at the rate it was set at…any information would be much appreciated.

For the tags in question, can you go into the gateway web page and check the device diagnostics to see if you have any scan class subscriptions that don’t look like they belong to the tags for that device. Also what kind of device are these tags coming from ?