Return requests anyone help?

Hi anyone help as this is new one for me. Had a return request the other day , no longer needed, the parcel was only dispatched that morning so they hadn’t even received it . Approved it straight away just waiting for delivery and then return. Parcel was delivered . This morning I had another return request, same order . How have they opened another return when I have already approved it ? And now what do I do ? They are both sitting in my return area if I approve the second one it will show as 2 refunds on the box but only one order.