Reply to pay it or to ask them to send proof? this is all really confusing to me and I don’t understand what to do

It’s from vanquis which I maybe had when I was 18 which is over 10 years ago, yes have moved many of times since then and never notified anyone because I don’t recall this ‘debt’ I checked my credit file and nothing about this I even have a credit card now which I pay and use no hassle, also have other credit things like my phone so I’m unsure how I’d be able to have them if this debt did occur many thanks

Hi, I have received a letter for overdale solicitor telling me they will take me court after 30 days if I don’t reply for a debt I don’t ever remember having and if it was mine it’ll be back when I was 18 and reckless more then 10 years ago. do I just ignore or what do I reply? What happens if I ignore and it goes to court? many thanks