Build a script for posting comments on Facebook posts

I'm looking for someone to write a script or an app to write comments of choice on Facebook posts(in groups). Posts are made by myself and have to get commented a specific amount of times in specific amount of time. For example user decides that he wants comment worded "Bump" "4" times in the next "17 hours" on each post he has made on a Facebook group. Comments will be made RANDOMLY within the specific time frame. Willing to spend no more than $100. Thanks for your time.