Hey @ankurgupta85,
We're sad to learn you left us! 
In the case of a negative balance on the account after a cancellation, a cheque is automatically sent for the refund to the address that we have on file. The refund is sent 2-3 weeks after the final invoice that shows the negative balance comes out.
If ever you moved and we no longer have the right address, you would need to make sure to update it. We can also send the cheque to an international address, but it'll be in Canadian dollars.
If your last payment was made by credit card, you can also request that the negative balance be refunded back to the same credit card by contacting us before the cheque is issued.
If any other method of payment was used for your last payment, we can only refund through cheque within the delays mentioned above.
Hope this helps!
