Refund not paid for over payment

have used Lendplus 3 times and all has been ok , till last week where i paid for my loan few days in advance and sent them the POP , however debit order still went off on the 25th i reported immediately and send through my statement and pop , tracey , fatima and assisf all ignored my quest. Later tracey advised 3-5 days for refund , it has come and gone. what is happening