Furlenco — Over charging

I have been using Furlenco since sometime in 2020, I was happy with the products. However, I decided on cancelling and they called me a gave me an Custom offer that gives me lifetime discount of 25%. The only reason I continued with my subscription.
Also on 22nd of March 2022 I decided to cancel subscription for one of the products and of course they told me, my subscription ends on 27th March and that I should give 7 days notice. Which means I will be charged for a whole month, when I called the customer service I was clearly told that it’s a policy and nothing can be done. So I was left with no choice. I had a bill generated earlier that day for Rs.3065.45 due by April 1st. But after I called customer service and obviously outraged by their condescending response when I checked the app after that, the balance increased to 3949.27. I called the customer service and they were as usual not helpful and told me that the lifetime customer offer was no longer applicable. So I asked if there was a policy I can look up, but not just the customer service, even the supervisor was not ready to help. Instead he told me that this is a management decision and no customer was informed about it. I do not agree with this as any change in service fee, change in a promised offer should be notified in case I do not want to continue with the service. So far I have made attempts to fcontact Furlenco and also reached out to CEO on Instagram but I have received no response. I need an explanation as to why was my offer removed and why was I not informed about the change and was left to discover it on the bill.