Enforcement agent putting a foot in the door
Do not grab, pull or assault an enforcement agent. An agent must not use force against a person, and entry to a home is usually restricted, but physical confrontation creates serious risk.
State clearly that entry is not permitted, do not open the door further and record events safely. Ask for identity and authority through a window or letterbox and preserve doorbell video and damage evidence.
Use 999 if violence is occurring or someone is in immediate danger. The civil remedy depends on the debt, entry power, force, loss and correct defendant.