Destroying coins in collision

[Ryan Makinano]

Hi guys! I am newbie to phaser and i would like to ask question and guide me in my project. I am currently developing a game for my project. My game will collect coins and coins that have question to be answered and will be evaluated if the user can play next level. 

Im using Tiled. And i am having trouble when the collision on the coins it increase the score multiple times before it will gone. Here is my code. Hope you guys help me.

    getCoin:function(){

        
        map.putTile(-1,layer.getTileX(player.x), layer.getTileY(player.y));
        score += 10;
           scoreText.text = 'Score: ' + score;
        
    }

It replaces the tile with a tile that didnt exist so i appears to be gone.