PERMANENTLY delete apps off iphone 4?

So i went to the purchases list in itunes store and deleted all the ones that i didn't want but when i look at how much space all my apps are taking up it is still up to 6.2 GB of room. I only have about 6 apps on my phone now that i actually use. So i want all that room back. I can still see them on my phone apps when you can check or uncheck mark them.

On your phone open settings, under the "general" option you will see "usage", tap it. You will see a list of your Apps and the amount of memory each one uses. Once you delete an App it is gone (hold it down then while it is wobbling press the X in the corner and tap ok).