No Service Suddenly/perhaps due to upgrade

I just had my service suddenly disconnected, i reviewed my account and I have no due balance (I even paid the next bill in advance just in case), and I have followed the troubleshooting steps. I don't want to have a technician come visit as I don't want the additional fee and I believe I can resolve this without one. My suspicion is that it is likely due to my plan upgrade. I upgraded my plan and now that i finally see the correct Mbps on my account (1000 to 1200), my service has been disconnected. Can anyone confirm if this is likely the case?