[Gingster]

You have to add: GivePlayerMoney(playerid, -100); (you can change the -100 to whatever)

PHP Code:

if(strcmp(cmd, "/refuel", true) == 0)
{
    if(IsPlayerConnected(playerid))
    {
        if(IsAtGasStation(playerid))
        {
            if(Gas[idcar] <= 99)
            {    
                TogglePlayerControllable(playerid, 0);
                GameTextForPlayer(playerid,"~w~~n~~n~~n~~n~~n~~n~~n~~n~~n~Re-Fueling Vehicle, please wait",2000,3);
                SetTimer("Fillup",RefuelWait,0);
                Refueling[playerid] = 1;
                //Using GivePlayerMoney(); is to give someone money, but if you put a - in it, it will decrease the money
                //GivePlayerMoney(playerid, 100); will give you 100$, GivePlayerMoney(playerid, -100); will take from you 100$
                GivePlayerMoney(playerid, -100);    
            }
            else
            {
                
                GameTextForPlayer(playerid,"~r~~n~~n~~n~~n~~n~~n~~n~~n~~n~Gas can is full",2000,3);    
            }
        }
        else
        {
            SendClientMessage(playerid,COLOR_GREY,"** You're not at a Gas Station!");    
        }    
    }
    return 1;
    
}