Found a fix... if you are good in DIY !
You will need to open your iPhone 5s to be able to view the volume button contacts, and slide something (I used a tiny piece of paper
) inside the gap that makes your volume keys jiggle....
You will need a pentalobular screwdriver
(the one that was required to open the iPhone 5) and a suction cup
(the kind that you stick on windows and mirror)... just follow the couple of steps on iFixIt website:
http://www.ifixit.com/Teardown/iPhone+5s+Teardown/17383
It worked for me... you must not be scared of opening your iPhone, and be careful enough not to break any connection wires under the screen (read the above iFixIt link for more info)
Unfortunately, if it's the power button you want to fix, you wont be able to do it my way
My power button jiggles a tiny bit, but it's hardly noticeable... when the iphone was opened I noticed there was no way to properly see the button and gain access to it