How do i delete the uninstalled apps from my purchased list on my ipod 5

I have major OCD when it comes to my things. And i have a ton of apps in my purchased section of my ipod where i downloaded them then didnt want them so i deleted them. I have deleted them off of the purchased section on my laptop so i only have the ones i want under there, but even after syncing my ipod a few times they are still under the purchased section on my ipod 5. I did download ios 7 so i dont know if it has anything to do with that. Please help me if you can i have been having major ocd issues for a little bit and it just gets frustrating sometimes.