Honorbuddy help..cannot use key or buddy auth

So I got a key in my email and it says its invalid when I try to use it to open honorbuddy its a 31 day key. then i go to buddyauth to make sure its the right key and i try to go through the register process but every time i put the email i used in it says "please use the email you used when purchasing your honorbuddy product key" ...what do i do. it is clearly the correct email considering its the one they key got emailed to. i used paypal if it makes a difference