New SQLite Database in an old application

I have an app that functions as a mobile phone book for a company. It was released with a preloaded SQLite database.

Now a year later we need to update the list of contacts. I updated the SQLite and released a new version of the application. I thought iTunes would update the database on the phone. I have users saying that this is not the case.

Was I wrong to think that iTunes would do that? Does anyone have any more information on SQLite and iTunes for me?