CONCAT Area Code and Phone Number

Summary

I want to combine an employees work, home, and cellular phone number so area code isn't a seperate column

Content

Using this forum topic https://cloudcustomerconnect.oracle.com/posts/2c226a667a I was able to use CASE statements to show all of an employees phone numbers in a single row.  Big shout out and appreciation to Caroline specifically - I used her method and formulas which worked perfectly.  Now what I'd like to do is combine the area code with the different phone numbers so I do not have to have area code as a separate column.  I'd like to add these to each of the phone types I have listed.  I've tried using the CONCAT formula but I had no such luck.