What brought this on - has it been intermittently charging recently like there may be a loose connection? Have you tried using a different (known compatible) charger or battery pack? If the battery has fully depleted, that'll explain why it won't switch on again (until its at least got a few mins charge in reserve at least). if the battery has gone fully flat and you plug in a charger, even then many devices won't switch on straight away so if you'vevtried a different, known compatible and working charger and got no-where, leave it connected and charging for 5 min before trying again to switch it on. Is this any help?
Have you dropped it, got it wet or has it been charging during a lightning storm (we've had thunderstorms in a big way where I live a few weeks ago)? Before it stopped switching on was it working fine and then you turned it off with some charge remaining or did it power off because it ran out of charge (or maybe during an update)? I'm trying to get at what YOU think may have bought this on. Did it have intermittent charging before it gave up the ghost altogether ie you had to wiggle the plug around sometimes to get a good connection? Sorry for the interrogation but answers to these questions should help to get to the bottom of whats happened.
never been dropped, just stopped charging/working, I've now bought a new Samsung charger and still nothing, I've even tried holding certain buttons for certain time etc and still dead, I need to send it to somewhere for a n internal fix.
If nothing that you're aware of brought this on, when you last shut it down, if it still had some charge left but you put it on charge, my guess is that a power surge down the mains (perhaps associated with a thunderstorm) may have fried it. You haven't stated the condition under which it failed - was it that it stopped charging ie the battery had become flat so it wouldn't power up and connecting chargers made no difference or it simply stopped working as in was working OK but then while you were using it, the screen went off and nothing you've tried will resurrect it. 'Stopped charging/working' doesnt give any leads as to whats going on.
If its just where you can take it in order to have it looked at professionally, Samsung have stores located in many cities within many countries. The Samsung website for your country will tell you where your nearest store is. I've never needed to have a repair undertaken but in my experience they did offer excellent training about my product at both of my 'local' stores.