(and Software Center and Ubuntu One subscriptions and other payments to Canonical)
I tried to buy something but it failed. What should I do?
How do I reinstall software I've purchased in the past?
Where can I view my purchases and my payment history?
Can I get a refund for my Software Center purchase?
Can I use Software Center purchases on other distros or other OSes?
I had some failed attempts to make a purchase. Could you cancel my incomplete transactions?
My purchase/install failed. How can I get more detail about the error?