Debt collector harassment / unfair practices

Typical aim: Cease harassment; comply with rules
Be specific: dates, times, order numbers, names, promises made, and the resolution you want.
We’ll reference:
Acts & laws: FCA CONC; Protection from Harassment Act 1997 (context)
Ombudsman/Regulator: Financial Ombudsman Service (for regulated firms); FCA
Guidance: https://www.fca.org.uk/firms/consumer-credit-consumers