Byjus Learning Online Products - Not cancelled the subscription

I ordered a neet **&** package from byjus. Their councillor come at my home and told us to take subscription right now and in future if we don't like their product we cancel within ** days of trial . We agreed and take subscription from them for this we make ***** payment and rest for ***** we take loan on my account .
As from the *th day when I received their package I raised request to cancel my subscription . I called my mentor Anjana Rathore to cancel my subscription as I wasn't able to continue my preparation as I'm currently doing job . She told me that our manager team will called you for the same. I get called up from Saurabh sethia sir on *th day after so many emails and calls. He asked me to show the payment proof I told him that I don't pay from my account. I pay this amount form third person. He again asked me to the proof so I share him the ss I got of in which payu reference is clearly mentioned but I don't know how it is not enough for them. Then I again email them to cancel my subscription again I get call from other mentor but still I'm not getting any response from them my cancellation .I received my package on ** March and I request them to cancel on ** March .