Flipkart - Executive denying for exchange old product but my old phone is eligible for exchange as per Flipkart

I have purchased mobile priced Rs **k. But i have seen an offer or exchange of mobile of **** extra off on exchange. Flipkart has given different values as per different conditions. They clearly mentioned that exchange price will be reduced if the screen and any other problems are seen at the time of pickup of old mobile. But when that Flipkart person has rejected my exchange mobile by giving unnecessary answers. I have told him to reduce exchange value as per Flipkart app shows. But he denied to do that and he rejected to pickup my old mobile. He said to give difference amount in cash and he wil give me my new mobile otherwise he will cancel my order. Here is my claim is that if the Flipkart is showing different values for different conditions then why they are denying to pickup my old mobile at reduced price. I am also attaching the proof that the Flipkart has its exchange policy stated that reduction issues and rejection issues. My phone has screen damage problem and minor body color problem from balck. So i understand that the value will be reduced. And i am also agree with that. But they are denying to pickup my old phone even if my mobile is switch on, model number is same as i provided to them, no any screen lock available, and imei also matched. Please help me in this situation. They are wasting my time.