Editing contacts creates a duplicate I have 5 different email accounts: iCloud, GMail, Hotmail and two others which my iPhone does not give the option to sync its contacts. 

So, I have only synced my contacts with iCloud and since barely a month ago, when I edit a contact it appears immediately a copy of it and if I delete one, both of the are deleted.

Does anyone know what is going on?
Does the duplicate appear on your iPhone or within your iCloud account. 

Try editing your iPhone contacts directly via this tool for example:

http://www.copytrans.net/iphone-contacts.php

Also, where do you edit the contact entries from which the duplicates result - on your iPhone or within the iCloud. I would assume that if you are editing them on the iPhone, a temporary local copy is created on your iPhone until it is synced back to the iCloud after which the duplicate copy (physically residing on your iPhone) will be gone.