Cannot sync iCloud calendar to iphone 5

I am working with an icloud calendar that is not syncing between a PC, iPhone or iCloud correctly.

- I edited my icloud username (email address) to match the Outlook email account I'm currently using for my calendar on my PC for clarity (I know this is not necessary but seems to be where the problem started).

- I logged out of iCloud on my iPhone and signed back in using the new edited username. Calendars is switched on.

- I used the PC iCloud application to ensure I was also signed in using the new edited username and had calendars set to sync.

As a result:

- In Outlook all my appointments are correctly set in a calendar called iCloud.

- On iCloud.com all my appointments are also correctly showing through a browser view of iCal.

- On my iPhone 5, there are no calendars showing other than 'Birthdays'. Calendars is set to 'on' in Settings>iCloud and Settings>Mail, Contacts, Calendars but no calendar information that I can see on iCloud.com is showing on my phone.

- As a secondary issue, the 'correct' syncing between Outlook and iCloud.com seems to be only for pre-existing events. Anything I have since added to Outlook or iCloud.com does not sync to the other.

What on earth am I doing wrong?