BHTV compliance notice from the HMCTS after 8 months

[Peppersmoked]

Wishing you all a good day. So today I received a notice letter from the HMCTS regarding an amount that I supposedly owe for reasons that I am not aware of. When I called them up they said its for some issue from July 2022. However, from July 2022 to January 2023 I received no information/letters/mails or notices - that's 8 months of new communication from anyone. Can anyone help me in understanding what I can do about this?

Just to give further context:
1: I was living in my university accomodation in July 2022 (when the supposed problem occured) - I still have no idea what though.
2: I moved out in September 2022 and before moving out checked for any pending letters in the mail room - there were none
3: From September 2022 to January 2023 I received no letters and no information - even after changing my address on my licence. That is 8 months since the "problem"
4: The notice was apparently issued on 5th Jan 2023 but I only received it on 12th Jan 2023 and now they are forcing me to make the payment in a couple of days without providing any reasoning

Any help will be really appreciated since these letters are sort of scary. Also could someone tell me what BHTV compliance is all about?

Thank you.

[Huxie]

BHTV = Bedfordshire, Hertfordshire and Thames Valley.

Do you own a car? Did you update the address on the logbook (V5C)?