Do the Apple Store replace faulty Apple Earphones with Remote and Mic?
I bought an iPhone 4s through o2 uk, where can I get a replacement for my earphones?
iPhone 4S
Enter your iPhone serial number here to see if you are still in warranty:
https://selfsolve.apple.com/agreementWarrantyDynamic.do
If you are, take the iPhone and earphones to Apple for evaluation.
Make an appointment at the Genius Bar to avoid delay:
Make a Genius Bar Reservation
http://www.apple.com/retail/geniusbar/
If you are no longer in warranty, you will have to purchase the replacements.