Redbus — not got refund since 3 weeks

Address:

Bangalore, Karnataka

I had cancelled my ticket on 5 Sep which I had booked from Thiruvalla to Bangalore . It is 3 weeks and I still have not got my refund of Rs2700. I have called up their customer service and every time they say they have already refunded but bank payment gateway problem. How can the bank have a payment gateway problem since 3 weeks? I will take suitable action.