Flipkart delivery partner scam

I exchanged my phone through flipkart the delivery partner came and he took the phone and told me that the exchange value will not be 12000 but only 9500 so he told me to pay on a scanner i asked him if i can pay the whole amount and not exchange the phone he told me that he had processed the exchange so now he can not cancel it so he gave me a scanner and i paid him 2500 . Now on flipkart it is showing that i have paid 12500 via cash and the exchange is cancelled which is not true becuase the delivery partner took the phone also and took extra money from me Delivery partner scammed me.