Air India - Refund not done

I had booked (cancellable) return ticket for wife and kid on *th October **** and the same was cancelled by me on **rd October ****. They said refund will be done in one week to the bank account but it is still not done. When I called to ask them, they told me that my money will be refunded in a month, but it is still not done.
Today **th March **** I called air India customers service and asked them about the refund they instruct me to call Chennai office *********** to ask them about the issue. When I called they give a different number to call same I called but no response from them regarding my issue. So I called the again Chennai office to ask them what to do but the lady who answered me was very rude and keep hanging my phone call. She even shouted at me for asking for a refund. This is already * month but still, I have not received my money. They are not even responding well to my issue. For me, I need a proper answer also now worried about losing my money because of your staff in Chennai office.