Iphone 5S doesn't always wake when I press the sleep/wake or homescreen button

Hey everyone. Had my iPhone 5S since launch day and im unfortunately having issues with the responsiveness of the home button and the sleep/wake button. I'll go to use my phone pressing either the home botton or the sleep/wake button to wake the phone and nothing happens for about 10-15 presses. With this being said, the issue doesn't occur constantly, it happens about 2-3 times a day, but still frustrating nontheless. Has anyone else had this problem with their iPhone 5S? I know it was a major issue with the iPhone 5. Also, I am a Vodafone customer.