I think I would need more insight about the type of industry your are in and your country’s view on work/Interning.

However, I would like to tell you to follow your gut and intuition. If you truly feel that you are not be valued and compensated enough, you have to either have that talk with your supervisor or leave. If you do decide to talk to them, have a hard number in mind that you will not budge from. Have your reasoning and analysis completed beforehand. Another option before the “talk” is to apply to other positions now. Once you get an offer somewhere that is more than what you currently have, use that to bargain with them. They will either see your value and attempt to keep you or not.

Lastly, you can leave. I would suggest to make sure to learn all the valuable skills and techniques that you can prior to leaving.

All in all, trust yourself 100%. If you feel devalued, chances are they are probably devaluing you. You do not owe them anything. Their main purpose is profits. They did not give you an internship to be nice. You earned the internship by either being qualified enough with the right skills, having strong personal connections, or luck (which is also a skill.)