(Boston, MA) Landlord charged bogus fees when I signed the lease, can I get that money back?

Greater Boston area. Single bedroom.

Signed the lease and moved in June. After noticing some issues with the unit, had the health department come in and look at it and they found violations. This cued me to look deeper than usual into the lease. AFAIK, it’s illegal in MA to charge anything but First/Last/Security.

I was charged $500 “admin” and am being charged $50 a month for “pet fee”.

As far as I know both of those aren’t legal charges. How can I get that money back? Or better yet, have my landlord put those into a deposit as if they were my security deposit? Does this require court or any specific legal representation? Is this even possible?

Any advice appreciated. I can give more details if necessary.

Edit: I was not charged a security deposit.