This is interesting because I recently brought up with my own company the issue with pay and the expected workload. I told them in a meeting that I thought they paid shit and expected too much, this was confirmed by the manager saying the number one reason for another department quitting was shit pay.
The company does not own you, if they want to waste cost to keep retraining people because they don't pay their workers fairly then so be it. Play your cards right, raise the concerns and document the responses (get independent third party opinions just make sure you are correct in your thinking). If they are shitty then quit and find another place to work and have no shame about never looking back.
Here is the important part though, make sure you are not the problem. If they give feedback take it onboard and again seek third party advice if its correct. If it is then learn and grow. Appreciate the workplace for giving you the feedback and the opportunity to grow as a person.