Meta tag viewport does nothing

I’m trying to get my website to be displayed at full scale in any mobile device

As of now, the website opens automatically zoomed-in, and my clients don’t like that. I thought adding the line

<meta name=”viewport” content=”width=device-width, initial-scale=1″>
would solve this, but it does nothing. I’ve tried playing with the initial-scale value to see if it worked and it does nothing. I’ve set it to initial-scale=0.5, for example, and it didn’t change the way the page displayed (to clarify, it doesn’t work neither on desktop browser nor on mobile devices).

I’ve been working on this for days, any help would be greatly appreciated!