Bigbasket.com — cancellation charge refund

I had placed order in bigbasket last month 19th march and the order no. Was mkoo[protected]. The delivery date promised on 24th of march. I was ok with the order with the situations as of 19th march. But in next 2-3 days situation worsened for corona effect. Things which i had ordered can not be accepted due to health safety reasons and i went ahead and cancelled the order on 21st of march. Bigbasket deducted 30 rs cancellation charge. I think they should not charge cancellation fee due to following reasons
1. When i booked the order, i was not aware about this new cancellation charge.
2. I tried to call multiple times to understand how they will deliver those items in current scenario. But their waiting time in call was 15 to 30 minutes
3. After cancellation i able to connect with customer service and they promised to waive the cancellation charge
4. The order was cancelled 3 days before delivery and there is no point of asking of cancellation charge
I was waiting till today to get back my total money, which is yet to refund back in my bank but not received anything yet and when called them they said they will give me call back for cancellation refund money but not received any call back. Hope this issue will be resolved soon
Mail id : [protected]@gmail.com