You're receiving the "Undefined symbol" error because 00200311 is not a string. The right(s, n) formula expects a string (s) and a number (n). You're giving it a number and a number. If you enclose the 00200311 in quotes, or reference a variable instead, it will work. Like so:
No need to go around setting variables here (unless you need to reuse the data somewhere else).
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...