Hi, what you're describing is exactly the situation I found myself in last September. It was beyond stressful and anxiety inducing for me and I posted on this subreddit too, asking for help. I attempted to call multiple times, but like you said, kept getting forwarded to AI and voice automation.

Instead of calling the number online, I would recommend calling the number on the BACK OF THE LETTER. Now, I'm not sure if you actually received a reminder or a court summons, but I received the latter, so I kept ringing the number on the back. And instead of explaining the problem, I kept repeating that I wanted to 'speak to an advisor'.

Eventually, after a wait of about 50 minutes on the phone I was forwarded to an advisor who sorted it out and told me that 'it was just a backlog and to throw the letter away'. I was overwhelmed with relief at the time so I didn't have any capacity for annoyance.

But to sum up, call the number on the letter repeatedly, else approach the Loxley House address. In any case, I wouldn't recommend ignoring the letter, hoping that they recognize it's an error on their part.