I'm looking for this song I've been hearing on the Musak where I work.?

It is; it's "Postcards from Paraguay" by Mark Knopfler.

You were correct! The singer of the song you are looking for is Mark Knophler. The song's title is Postcards From Paraguay and was released in 2004. Here are the full lyrics...

one thing was leading to the next

i bit off more than i could chew

i had the power to sign the cheques

it wasn't difficult to do

i couldn't stay and face the music

so many reasons why

i won't be sending postcards

from paraguay

i robbed a bank full of dinero

a great big mountain of dough

so it was goodbye companero

and cheerio

i couldn't stay and face the music

so many reasons why

i won't be sending postcards

from paraguay

i never meant to be a cheater

but there was blood on the wall

i had to steal from peter

to pay what i owed to paul

i couldn't stay and face the music

so many reasons why

i won't be sending postcards

from paraguay