Unwelcome thing to do, if not exactly usury (5)
I believe the answer is:
usurp
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for usurp that I've seen before include "Seize power illegally" , "Appropriate without authority" , "Arrogate" , "Oust" , "Take over - misappropriate" .)