Flex Box wont connect since changing plan

I changed my service plan to the "NOW" plan yesterday. For some unknown reason I am now unable to get my Flex Box to connect. I've tried : connecting via Wi-Fi, connecting via Wi-Fi after pressing the WPS button, disconnecting and reconnecting power, restarting Xfinity modem/router ... as well as doing all of the aforementioned while "hard wired" with Ethernet cable. It (the flex box) keeps displaying "Lets get your entertainment back up and running" I call the 1-800 number and it keeps saying "I see you have a modem restart in progress, call back in 10 minutes" 

I could sure use some help or advice (I've tried every start / restart , connect / disconnect combination possible)

Thanks!