I purchased Infinity blade befor long time and now I want to download it Again but it ask me to purchase it again so Please help me or Refund my money !!?

Do it here

iTunes Store Support

http://www.apple.com/emea/support/itunes/contact.html

For few days in App Store infinity blade was free. You must check your email about purchase that and report your problem in 48 Hours will refund your money

The only reason you might be charged for downloading it again is if you changed to a different iTunes store account. And if you did you must pay for it again.

Have you tried re-downloading via the instructions here?

http://support.apple.com/kb/ht2519

Do you live in a country that allows redownloads of movies?

Learn more about which content types are supported for iTunes in the Cloud by country, as well as where iTunes Match is available.