This isn't an Apple problem so no need to call Apple. It's an iTunes problem. iTunes is supported separately from Apple and you need to go through iTunes.
Go to the iTunes support page at apple.com/support/itunes for help with this.
Also, make sure you change your iPad settings to not remember your password in iTunes. If your iPad is stolen, anyone can access your account if you leave your password unprotected.
If you need help figuring out how to change your iTunes settings go to the above-mentioned support page.