If you have resided in the U.S. and was considered a U.S. citizen. Worked there for let's say 10 to 15 years and have been deported? What happens to your social security you have been garnished? Can you get that back from them and how?

You paid into the system for social security and were not "garnished". I'm assuming you were deported for reasons related to something you did not do properly, or something you did do wrong, or whatever, but since you were deported, you forfeit those monies.