Counting Cards is bad

Tell us what’s happening:
Hello there, I have tried to solve this problem many times in different ways. Switch and If/else. Doesn’t seem to work either way. Tried going off what others have done, doesn’t work either.
Some guidance would work.

Your code so far

var count = 0;

function cc(card) {
  // Only change code below this line
  if (card == 2 || card == 3 || card == 4 || card == 5 || card == 6){
    return count += 1;
  }  if (card == 7 || card == 8 || card == 9){
    return count += 0;
  }else if ( card == 10 || card == 'J' || card == 'Q' || card == 'K' || card == 'A'){
    count -= 1;
  }else if (count <= 0){
    return String(count) + 'Hold';
  }else {
    return String(count) + 'Bet';
  }
  
  return "Change Me";
  // Only change code above this line
}

// Add/remove calls to test your function.
// Note: Only the last will display
cc(2); cc(3); cc(7); cc('K'); cc('A');

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/counting-cards