Deleting an account!

Whilst trying to reinstall my PS12 Programme I made a mistake when entering my email ID.  I have not been able yet to find out how to delete it and when I enter the redemption code for my PS12 Application it is not accepted and states that another ID has registered it,  the other ID being my proper ID. so I am not able to get a serial number for it.  Help please.   John   (85)