I after having my account since BC i started using some programs found on here to make the game more ''fun''. and eventually got banned. Here's what i did to unban my own account, hopefully this works for you too.
This worked for unbanning my account after i got banned for ''3rd party software'' (xyz hack)
1. Your (banned) account must be merged with battle.net account
2. Create a new account (it can be a trial account) with the same info (name, etc) as your banned account.
3. Merge it with your old (banned account) battle.net account
4. Play on the new account for a few hours.
5. Give your account info away on some scam site, once they log in (pref. from a diff country) your account will be locked and you will need to change your password to unlock it (don't)
6. Call blizz and act suprised your account was hacked, they will ask you for your information, etc. and will ask which account you want unlocked (since you now have 2 wow accounts on your battle.net account) just tell them you want all the accounts unlocked
7. Enjoy.
It may not work if you have tried to unlock your account previously with no luck and your account was ''perma banned'', but it doesnt hurt to try
credit goes to fedelis for this method