Bigbasket.com — canceling the order without telling me

I ordered 70 items worth 7700 rs on 29th june 2020. And they promised me to deliver the items on 30 june 2020 4pm to 7pm slot. On 30 june 2020 at 10 pm i got the message that order was cancelled. With out asking me anything they cancelled the order. And they put my amount in their big basket wallet. How can they will do this? If they dont have sufficient amount to do business ask us we will do some charity but dont cheat the people by doing all this silly things.