Porting landline to mobile

Why does Xfinity not fix the porting issue?  I have been trying to port my Comcast Business landline for 16 days and my business number has been disconnected for 7 days.  The porting process has been started over 3 times and now I am held hostage because I cannot even close the account unitl the port has been completed.  This is my business, how I make a living!!  I have spent over 10 hours on the phone and in the Xfinity store to try and resolve this problem.  Why do you not have ANY upper level customer service?  I'm not sure how you retain customers doing business this way.  The internet is full of complaints as I'm certian the FCC and BBB are as well.  You are way behind the curve in technology and customer service!!!