Indian Railways — reg refund amount of cancelled ticket

I had booked a train ticket on 09/02/2019 in Garib Rath Exp (Train No. 12517, DOJ : 16/05/2019). but i had cancelled the ticket on 10/05/2019. the refund amount Rs. 1370/- supposed to be credited within 3-4 working days, but it's not yet received. i had contacted with IRCTC through email in which they had replied that they had already refund the amount to bank. when i contact with State Bank of India customer care they replied that they can not entertained regarding this, asked me to contact IRCTC