My phone Lumia 720(India) isn't restarting after the cyan update. What to do.?

[Manindra Kumar]

My phone Lumia 720(India) isn't restarting... After the two setting acres rotate... The phone restarts right... At this point my phone isn't restarting... It is repeatedly restarting.... And after 15 or so such restarts it showed an exclamation mark(!)... And the above process started again...

 

[worldspy99]

Use Nokia Software for Retail to reset the phone to factory settings.
Here are links:

Nokia Software Recovery Tool updated with support for Windows Phone 8.1 and more! | Windows Phone Central

FAQ - How can I recover/reset/restore my phone software? - Nokia - USA

Good luck.