Go read these
discussions.apple.com
Learn what to do if you see an alert when trying to create an Apple Account or set up iCloud on your iPhone, iPad, or Mac.
support.apple.com
You are not allowed to create a certain number of new ID's within 1 calendar year. When you try to make a new Apple ID, it's grabs the serial number of the device you are trying to create the Apple ID on. In your case, it appears Apple has the iphone's serial numbers already in their system and is doing it's usual checks against the iphone's serial numbers and is reporting back that too many Apple ID's have been created using those iphone's.
You need to look at it this way. If you are the owner of multiple Apple devices, you only use your Apple ID to log into each device. Thus, if you've never had an Apple device before it stands to reason that you would create an Apple ID on the device that you just purchased. Now, you've created your Apple ID and now you can start using your device. Now look at it from Apple's point of view. If you've just created an Apple ID on a purchased iphone, why would you then try to create a new ID on that same device? you wouldn't unless you sold the iphone and the new owner was trying to create a new Apple ID so they can use the device. So in your case, according to Apple, your iphones have been handled by multiple people in one year who have all tried to create a new Apple ID. It is a good security feature because your iphones could have been stolen and passed onto multiple people within a year who all tried to create an Apple ID.
You will need to contact Apple support to get the issue resolved.