Hmm I fear the black button is broken and no longer captive in the surround hence the glued in button. You could very gently insert a fine knife blade around the edges of the switch to see if it will gently pry off the glue. If it does come loose and is not captive then tape over the top of the button will hold it in place.
Must admit if I bought what was supposed to be a working switch I would not be impressed and would be looking for a refund.