Apple - Order cancelled by wishmaster without asking me

Hi, I ordered apple iPhone ** blue colour *** gb during big billion days sale for rs ***** (including ****₹ as exchange for my MI note * pro)
It was supposed to delivered to me on *th October. And wishmaster came on *th and he said he'll give only ****₹ in exchange of my older phone. Then, he laughed and said you've two options, either sell it somewhere else for higher amount or change your screen by tommorow, I'll come again and may offer you higher prices.
But then he never came back, never called me again and simply after * days I receive notification that wishmaster has cancelled my product, because I refused to take it. That's a false statement and there was no verification on this from my side but still it got cancelled. I wanted that product anyhow,, but now they say it can't be reinstated. Please help.