Furlenco Rant! Need Suggestions.

My furlenco tenure was getting over hence I bought similar items from furlenco before the tenure ends.(Didn't want to renew it, wanted new one) They never came to pick up the old items. I called CS team they said they have raised a request for pickup. 2 days later they pickup the items. In the app I see an outstanding bill. When I enquire about the same. They tell me as per the T&C you were supposed to return 1-7 days before the tenure ends. I had to call them on the day of tenure end and remind them please take it back. The funny part is the new items came on the day tenure ends (very quick to operationalise this) They called me a gazillion times to remind me to renew the old items before tenure ends. Not once they called to tell me that return has to be done prior. I tried convincing the CS team that I bought the new similar items from furlenco itself. No response. They're rude sometimes. I believe this is a dark pattern. Hiding relevant information regarding payment in T&C. Not reminding the customer once about the consequences. I asked one of the CS members if they think this is fair. They said no it's not fair, but system is like this. What do I do now? How do I take this forward? Anybody from furlenco who could help?