The issue is they wanted you to submit the SLR WITH the acceptance. You submitted it 6 days later. That means they needed the SLR immediately because THEY were on a timeline.
If the language and condition on the acceptance “letter” said to submit the SLR at the same time, you may not have a leg to stand on.
From the UCOP (The process for determining residency | Understanding residency for purposes of UC tuition):
The process for determining residency
“UC determines residency based on information you provide in the Statement of Legal Residence (SLR) — a form all new students submit (usually online) to the campus residence deputy in the Office of the Registrar. You submit this form after committing to a campus by filing your Statement of Intent to Register (SIR).”
Email the dean of undergraduate admissions, Blia Yang and explain your error.
Call the staff and confirm your SLR status.
I wish you luck!