We can recommend vendors all night long, but you are not guaranteed anything! This is the joy of dealing with China products, some are great, some are junk, and it will vary batch to batch, such is the life of e-cigs right now! The vendor's can't open and test every product they get in before they ship it. Watch any of the vendor forums, the bigger they are the more complaints they get about how this or that is junk and they want it taken care of now! How they resolve these is all we can go off of.
You buy a camera for your friend for Christmas, it doesn't work, is this your fault? Nope! Is it the stores fault? Nope, the manufacture dropped the ball and let it slip through the cracks, then the store is left holding the bag. I'm not saying it's right, but it is what it is and all the vendors can do is try and make it right with you as best then can!
I've dealt with My Freedom Smokes and had great luck. I've dealt with Vapor 4 Life and had great luck! Ikkenvape, Altsmoke also great luck with them. When I have had problems they always tried to take care of it as quickly and fairly as they could.
As for pulling up the center pin, this is a pretty common fix for problems with these batteries. As long as you don't hit the fire button while you are prying on it there's not much risk involved.