Corrupted Ring Tones

A number of tones on my N6021 have become corrupted - no wonder I wasn't
getting any calls.

How can I restore these at zero cost and without the benefit of a phone to
PC lead?

TIA.

Chris.

Well guys if you are looking for a cool stuff ,where you can download various ringtnes for free.There are various categories of ring tones where you can download and personalize the ring tones,Nothing expresses your personality like a cell phone that rings with your special song. With the latest technology you can choose just about any song from any source you choose.