Hi skeeweeaka,
It sounds like you just need to revise the header text of your store window. To accomplish this, please go to Auctiva -> Store(Tab) -> Edit Store Window, revise the "Header Text" field, and save your settings.
Once you have done this, your new header texxt will be updated on your current listings the next time the store window refreshes, which it does about every 2 hours.
-Mike