England, being made redundant but found a new job early, desperately confused about whether I'm entitled to a payout

England, employed at my current job for 4.5 years

I was informed in November 2025 that the site I work on is closing with operations being moved to another site a few hours away. We had the two weeks consultation and it's still going ahead.

This is where it starts confusing me, the planned date of closure is November 30th 2026, I had it confirmed in writing from a letter confirming a promotion would be permanent until end of my contract on that date.

I didn't want to stick around so put in my notice a week ago after finding a new job, am I currently entitled to statutory redundancy despite not staying until the end? Our HR manager has said no but I wanted to be absolutely sure before I believe them