TLDR; I went to treatment unexpectedly and was unable to fill out my LOA or medical leave paperwork. My manager told me it was unnecessary and everything was fine, except oops, you lost your raise because you (or your abusive parents) didn’t file any paperwork. what do i do

In October, I was taken by transporters (came in at 2am, no warning) to a (primitive) Wilderness Therapy Program. I stayed there 13 weeks, and afterwards i was sent to a year long transition program but only stayed there a month and a half. I was 16 when i was transported and i celebrated my birthday in February. I knew my mom had the power to apply for medical leave or a LOA for me while i was literally miles from powerlines or roads that weren’t dirt. i begged her over letters, which had a weird delay because of the therapist giving me their letters and mine going out the same day, meaning i couldn’t reply until another week later; that made solid answers take two or more weeks to get to me. the only actions she took were calling my manager twice (he didn’t pick up) and visiting my store once just to ask for him and only telling one shift where i went. obviously i was sent in part because of my awful relationship with my parents, and at the time i really couldn’t trust them for shit. my mom kept forgetting and eventually i just gave up. after i got home, march 1st, i took time to adjust to life back at home before trying to get back with starbucks. my manager from before (who literally felt more like a father to me than my own😅) transferred to another store ~30 min away and was replaced by Steve. Obviously this was gonna be an obstacle but i had no idea how huge. i started applying and lobbying the shit out of steve to help me (getting the option to apply took weeks on its own, the system was messed up and there was no option to apply as a barista when i looked up my store. steve acted like this was completely out of his power and it took me roping in my old manager who had his own things going on at his own store to get that option up.) after i applied successfully, i had to do it AGAIN because steve couldn’t find it. a few more weeks of badgering him for an interview, and i got my first sip on memorial day. and my sister in law pointed out to me that i SHOULDVE gotten an interview so i could discuss my pay and have a chance to negotiate it. weeks later, after seeing my paycheck and feeling the suspicion that not everything was back to normal, i asked steve to check my hourly pay in front of me, just in case. and my fears were right, i was back at base pay.
Brief Wage history: i started at 10.50 5/11/2021, then in august there was a regional base pay raise to 12 and partners in the region hired before july something 2021 got a percentage bonus because we were doing spectacularly in sales, so i went up to 12.60$.
I’m so overly pissed. I had asked steve how i could apply for a past medical leave or if there’s any paperwork i can do to mark myself as not fired and in treatment from october-march and he said “we’ll deal with that when you get hired”, “we’ll deal with that later”, “oh! you don’t need to do that, you’re back as everything’s normal, you were marked as rehirable so it’s not a stain on your record.” and then when i asked to see my pay and he blubbered an explanation, he said that because i didn’t do LOA or medical leave paperwork i lost that raise. so i did fucjing need it!!! and nows when he tells me oh we can’t go back in time to do that, it’s beyond my power, but i’ll call partner resources and try i guess. i have to come up to him because he hasn’t gotten back to me at all, and that’s when i corner him in the back room asking him what’s the update. the way he spoke i’m so sure he actually didn’t do shit. and he treated me like i was being petty, 60 cents is so small and you’re getting the raise to 15 on august 1st anyways! even though i’ve been back almost 2 months and that fucking makes a difference. Steve keeps saying things are out of his power as an excuse.. does he not realize he’s two levels above me and if he can’t reach up there i sure as fuck can’t? and i KNOW there’s never nothing to be done, especially in special cases like mine. I’m so fucking distraught, after missing actual months of work being in treatment, i come home and i have to work to get everything back to normal, and i’m finally told great!! after working your ass off everything is back to normal even though it fucking wasn’t. i just know my old manager would’ve had my raise reinstated and i would’ve been compensated for the time i didn’t have it by now. please help me.