DUN

DUN, used as a verb, means to ask for repeatedly.

For example:

"And the industry succeeded earlier this month in persuading Missouri to pass a law barring its cities from dunning them for taxes."

http://www.npr.org/templates/story/story.php?storyId=128847984&sc=nl&cc=nh-20100730

or

She dunned her father for a shiny car to impress her new found friends.