Byjus ias - Not cancellation of subscription

I have bought upsc subscription from byjus for ***** rupees in mid September ****, first two months I was convinced that their services aren't good and I tried reaching the rep named suman to cancel the subscription but she didn't receive any call or reply me,in January the tab was broken I directly called their customer care to cancel my subscription as my tab was broken,it is irreparable and I can't afford to buy a new tab, they said that they will give me a call back after discussion,but still emi was deducted even after my cancellation request for further * months and I started getting calls from a third party stating that I have to further pay the emi for * more months,I called them back on ** the August **** because I was not able to contact them as I was hospitalized due to covid, they said that their subscription can't be cancelled after * months, when I told them that it is within * months,they are saying that cancellation request should be done within ** days,I am not even asking them to refund the amount deducted even after my cancellation,iam just asking them to cancel my subscription so that the third party won't call me to pay * more installments but they are refusing to cancel the subscription and asking me to use their mentor service more efficiently when I clearly mentioned that I was not happy with their services.the third party calls me everyday to pay the emi or else ask them to end your subscription.i don't know what to do ,these persons are torturing me even after I have paid them more than their services when my financial situation is worst