I had the same issue, which kept me wondering why I didn't get any kind of confirmation for entering a support ticket. When I was asked for "further proof" I uploaded my invoice and coupon in the attachment section of the form.
I thought the problem might be the browser: The phenomenon occured with the latest Firefox and Internetexplorer which are the ones I tested for this.
When I tried it with with Google Chrome though (Version 34.0.1847.131 - Portable), I got an error message which stated that the filesizes of both my attachments were over one MB which happens to be too big.
This error never occured in Firefox or Internetexplorer!
After trying again, this time with adjusted files, I got to the page where it confirmed my ticket entry and I received an confirmation E-Mail which contained all my entered data immediately.
Further than that, I didn't get any response but I still hope this helps you and if not then I apologize in advance for wasting your time.
Insert badass signature here --> <--
05:50 AM by