Legal Question in Criminal Law in California

It sounds like there is still an active warrant for your arrest. Although you scheduled a court date, officers can arrest you on the warrant until a judge formally recalls it.

I don't think it constitutes harassment if the police are trying to do their jobs by serving an arrest warrant.

Please understand that this is a general discussion of legal principles by a California lawyer and does not create an attorney/client relationship. It's impossible to give detailed, accurate advice based on a few sentences on a website (and you shouldn't provide too much specific information about your legal matter on a public forum like this, anyway). You should always seek advice from an attorney licensed in your jurisdiction who can give you an informed opinion after reviewing all of the relevant information.