If its someone you employ, and you seriously hate, them fire them. If it is a collegue and its just the way they work than you have two options to do (go with number two.). 1) Find something that really annoys them and whenever they annoy you, annoy them back. 2) Talk with them about it. Find out what your problems are and work it out. If they are just being an idiot about it then you can stop working with them or deal with it really.
If you are two seperate businesses, then take note all you need is one person to get mad at you and they can destroy your entire business.