My account keeps being high jacked by someone in America and I have to change my password every week how can I stop this

What makes you think the account is being "hijacked"?

If you really think that's what's happening, then use a more complex password than the ones you've been using.

Make sure to change your email passwords as well, but not to the same password as your apple ID has.

Log in to your Apple ID from a web browser and make sure your recovery email is yours. If not, change it ASAP.

https://appleid.apple.com/

If you take a few minutes of time to reset and set appropriate security questions not only on your Apple ID, but your email addresses also, I'm sure you will fix the problem permanently.

I'm very sure that changing all that does not stop it happening. Twice a week, I have to change passwords because I have been told that 'Someone in (pick any country in the world) has downloaded (pick any stupid game) using your account - we advise you to change your password.' I now have half a notebook full of passwords that I have used for my Apple account, every one of them more complex than the previous one. I am now on 25+ character passwords with symbols, number & letters in totally random sequences that I have no chance of remembering but it still keeps happening - I want out of my Apple account but, although everyone else seems to be able to use my account, I am not allowed to delete it - what a load of rubbish it is.

You should be able to call Apple support and have them delete it, just tell them you think the account was compromised and want it deleted.

Sounds like youre responding to phishing emails... not actual notifications from Apple.

I would agree.