Tamil Nadu State Transport Corporation [TNSTC] — Bus ticket booking failed but Money not refunde

I booked bus from Tirunelveli to Chennai Kilamabakkam on[protected], once I booked the seats and tried to pay, the payment server crashes .After reloading, I was able to make the payment, but the status said failed. The website said on Failed transaction, the money will be refuned in 3 - 5 days but still didn't get any refund. This is my OB ref no.: OB31031201