Problem when rotating an object continuously

I created a circle to be rotated 45 degrees every time I click the arrow, either right or left.

For this done, I'm using CSS and jQuery. ( SEGUE FIDDLE )

I made the following function spin(direction) to include any of the directions clicked on the arrow by the users, so much so that I came across the issue of discovering the degrees of an element and knowing only in matrix format, format by which javascript return and search, I have adapted a function for matrix -> graus conversion. The code works perfectly!

The point is, when I click many times, either right or left, after a certain number of clicks, the circle twists in the rotation, and always hangs with the "come and go" movement, increasing and decreasing degrees , and I can not break this vicious cycle of the event. I made the fiddle above so that you can simulate what I am interpreting here!

Below is my code:

$("#turn-spinner-right").click(function(){
  var sentido = 'right';
  spin(sentido);
});

$("#turn-spinner-left").click(function(){
  var sentido = 'left'; 
  spin(sentido);
});

function spin(direction){
    var transform = $(".spinner").css("transform");
    console.log('MATRIX: '+transform);
    var angle = convertMatrixToAngle(transform);
    console.log(angle);    

    switch(direction){
        case 'left':
            if($(".spinner").css( "transform" ) == 'none'){
                $(".spinner").css("transform","rotate(-45deg)");
            } else {
                var newAngle = angle-45;
                console.log('novo angulo:'+newAngle);
                $(".spinner").css("transform","rotate("+newAngle+"deg)");
            }
            break;
        case 'right':
            if($(".spinner").css( "transform" ) == 'none'){
                $(".spinner").css("transform","rotate(45deg)");
            } else {
                var newAngle = angle+45;
                console.log('novo angulo:'+newAngle);
                $(".spinner").css("transform","rotate("+newAngle+"deg)");
            }
            break;
    }
}