BB Daily - Services terminated without intimation

I had subscribed for milk delivery for more than * years now from BB daily. I had more than ****/- wallet balance in BB daily. On *st July, I didn't receive my delivery , after calling BBdaily they apologized and promised regular services, Again on *nd July I did not receive the delivery , again same apologies and promises for regular services. They also told me about my device details, android version and asked me to update the app. On *rd July receive I could not see any orders pending in the app. After calling BBdaily, i was told that my services are terminated. On asking the reason they couldn't give any specific reason. I asked about why did they not even inform me, but they did not have any satisfactory reply.
I asked them to refund my wallet balance. But out of total Rs ****.** they refunded only Rs.****/- and retained Rs ***.** . They said this is the cashback which I have received since beginning.
Now I have * concerns.
*. Can BBdaily terminate the services in spite of me having adequate balance in the wallet ? And if so, is it not BB daily's responsibility to inform me in advance that they do not want to provide services ? How can they just stop delivery without sending me any intimation. Even on *st and *nd July, that is after stopping the services, they did not tell me about the termination on call/chat (I am attaching the chat here)
*. How can they not refund the cash back amount which I have receive by way of valid offer over the period ? This is not after the termination of services, In fact they still keep me sending cashback offers.
Hence I want to file a complaint against BBDaily, for the unprofessional behaviour by not informing me, due to which I had to suffer for * days.