mysql group by on certain condition and column value

Question

There are 4 receiving methods. 1) delivery 2) pickup 3) mobile_topup 4) bank_deposit

if there are 2 mobile topups there I need only one. But, if there are 2 delivery methods then I need both f them. To achieve this, I have created this query:

$clause = "SELECT id FROM beneficiary_payment_info
           GROUP BY IF(ben_payment_method='mobile_topup', '', ben_payment_method)";

But, the problem is, it's group by with delivery methods as well. I don't want that. Right now, I have 2 mobile_topup , 2 delivery and bank deposit in database.

I need 1 mobile_topup , 2 delivery and 1 bank deposit .

I was just wondering that is it possible in this query or I need to do it in php ?

EDIT

temporary, in php I have this solution. But, it doesn't look reliable.

$mobile_count = array();
for($i=0; $i<count($data); $i++){
    if($data[$i]['ben_payment_method']=='mobile_topup'){
        //unset($data[$i]);
        array_push($mobile_count, $i);
    }
}
if(count($mobile_count) > 1){
    for($i=0; $i<count($mobile_count)-1; $i++){
        unset($data[$mobile_count[$i]]);
    }
}

Answer 1

$clause = "SELECT id FROM beneficiary_payment_info
               GROUP BY IF(ben_payment_method='mobile_topup', ben_payment_method, id,)";