Deposit discrepancy - was Iwrong?

** Thanks everyone for your input. I can recognize that I was wrong in this, which makes me feel worse about what younger me did. We don't talk anymore cuz our communication was terrible but I hope one day i gain the courage to apologize for the things I did wrong. **

This happened several years ago at my first apartment ever. My friend, we'll call her Mandy, had an extra room and wanted a roommate so I decided to take the plunge and move in. Originally the landlord, her boss, had said no deposit was required. But when he saw I was moving in he said he needed a $2000 deposit. Mandy felt bad that we were told with short notice so we agreed that she would give $1500 and i would give $500. Fast forward a year later and we have to move out because he's selling the condo. Since Mandy and I weren't used to having carpet and didn't know how to care for it, our landlord had to replace the carpet because we left it pretty filthy. I believe he kept $500 of our deposit. My roommate said it would be $250 each so I would get back only $250 and she'd get back $1250. I agreed but after a few days of thinking about it, I didn't think it was fair that 50% of my deposit would be gone when the landlord was keeping 25% of $2k. To me it made sense that 25% of my deposit would be taken out and I should get back $375. My roommate would aso give 25% of her deposit so she would get back $1125. When I talked to her about my thoughts she was a little thrown off. I explained it wasnt fair I lose 50% of my deposit if we split it $250 each. I could tell she didn't like it but my math was adding up so in the end she agreed.

Anyway, that was the beginning of our downfall unfortunately. After 4 years of living together and me giving into all her wishes and needs, essentially letting her get her way, we finally moved away from each other and no longer talk. Also it's late so sorry if I messed up the numbers.