Gst debited from bank account not credited to cash ledger

Yesterday, we created challan and deposited IGST online, but GST site is so slow, it hung up in the middle and came up with a General error saying `Sorry for the inconvenience' (screenshot attached), but the amount was debited from the bank account. Now the Electronic Cash Ledger balance is still zero till today. So wondering how to fulfill the requirement of filing GST 3B Return before Aug 20? Experts please help.