Gst refund

We are collecting GST for auditorium rent and remitting it. As GSTR 3B filed late we paid late fee. By mistake we remitted more amount as late fee. The balance is there at electronic cash register under the head FEES. But we can't utilize the amount for payment of tax . How we can use the balance available for tax payment. Or whether we have to file request for refund. If refund request needed please explain the procedure.

Thanks in advance

Antony Kaitharath