I thought when countries contributed peace keepers to the U.N. it was a contribution. I was surprised to discover it's seems to be more of a rental for some countries.

"Member states contribute the personnel and receive monthly payments in return."

https://web.archive.org/web/20150913050425/http://america.aljazeera.com/articles/2015/9/11/un-chief-will-repatriate-peacekeepers-over-sex-abuse.html

If countries weren't acting as mercenaries and were not reliant on the money, how is repatriating troops and with holding payments and blocking them from missions a punishment?