I can't update my iPhone to iOS 8?

My phone says I have the latest update, but I'm still on iOS 7, i have an iPhone 4. What could be wrong?

Be careful with this as iOS 8 is not compatible with iPhone 4's and older models.
My company has a Tier 1 & 2 Wireless Service Desk for our Clients and too many have found out the hard way that iOS 8 can brick older iPhone's. It could be that Apple is blocking your update due to the incompatibility.
Don't be too hasty - research the bahookie out of this before pushing for the update or you may end up with an expensive Apple paperweight.

IPhone 4 isn't compatible with iOS 8. You will need an iPhone 4S+, iPad 2+, or iPod Touch 5th generation.

IOS 8 is only for iPhone 4 s, 5, 5s, 5c and above and not available for iPhone 4 model.

iPhone 4 can't get an iOS upgrade unfortunately.

You can't update iPhone 4 to iOS 8. IPhone 4s is the oldest iPhone model that can be updated to iOS 8.

Throw your phone into the toilet and buy a samsung scrub

READ BEFORE YOU INSTALL. IOS 8 IS NOT FOR IPHONE 4. PERIOD… You are outdated. Get over it!