Cancel activation/port number process

Does anyone know how to cancel the activation/port number process online?  We entered the incorrect security pin.  I've been on hold for 2 1/2 hours waiting to speak to a Xfinity Mobile Rep. 

Background - Switching from Straight Talk to Xfinity Mobile with new phone purchase from Xfinity.  Couldn't find security pin on Straight Talk so used last four of SIM.  Finally located correct pin and need to revise the info on the activation but can't find where I can stop or correct.