Mojang hasn't responded in over four months?

Is anyone else having this problem. I bought Minecraft in 2012, and this past January I decided to change my email and password, but when I logged on, it said can only play demo. I gave Mojang my transaction ID, but those ******* haven't responded since. I regret buying Minecraft because of this stupid ****.

Oh right! There's a demo now! Use your old email and password. They won't transfer your premium membership between accounts