Q: Due to circumstances I have three iCloud accounts, How can I amalgamate them into one iCloud account?

You cannot merge different iCloud Accounts/Apple IDs, Apple won't let you do that. Just delete the accounts from your device that you don't need ("Settings > Mail, Contacts, Calendar") and keep the one you want to use in the future. ("Settings > iCloud")

No, unfortunately you cannot merge accounts or transfer any purchased content from one account to another. As I said Apple won't let you do that.

See also here: http://support.apple.com/kb/HT5622?viewlocale=en_US

I have multiple Apple IDs. Is there a way for me to merge them into a single Apple ID?

Apple IDs cannot be merged. You should use your preferred Apple ID from now on, but you can still access your purchased items such as music, movies, or software using your other Apple IDs.

If you are wondering how using multiple Apple IDs relate to iCloud, see Apple IDs and iCloud.