cant change my email

HI

well i wanted to change my current email address since i don't remember it and when i did it says a confirmation email is sent to my old email address. since i don't remember it i decided to submit a ticket. Here's the problem

when i was filling out the details it asks for my current email address (which i dont have and i need to change it)
and also for recent purchase. i have never purchased zp but am planning on so i thought i would make sure every thing is in order in case i have a problem later on...any ways...i cant leave the fields empty so i cant submit a ticket. All i need is the email address.

please help..
awaiting instructions
Roman