Everyone has people they don't get along with and people who work at cross purposes to them. Maybe it's personal or maybe it just has to do with conflicting priorities and roles. For these situations, we have conflict resolution techniques.
Regular conflict resolution techniques don't work on somebody who isn't playing by the rules of civility and human decency. Here we offer resources to help you figure out whether you are dealing with a bully. If you are, do not attempt to cope with it by yourself. Talk to a supervisor that you trust. With them, you can decide whether, when, and how to involve Human Resources.