In the following songs workers don't quite seem to get what they earned:
"The Old Chishom Trail" they cowboy is nine dollars in the hole at the end of the cattle drive;
"Drill Ye Tarriers, Drill" the worker is docked for the time he was up in the sky;
"Sixteen Tons" the miner owes his soul to the company store.
I'd be interested in hearing about other songs that have this (sub)theme in them.