A “notice of intended legal action” from a powerless, bottom dwelling debt collector such as DCBL is nothing but the type of rubbish you have been told to ignore. Anything from a debt collector should be ignored and binned.
When you receive an LoC, which will give you 30 days, not 14 days to pay, then that is probably the LoC. Oh, and it will be titles “Letter of Claim” or “Letter Before Claim” or some such title.