Paytm Mobile Solutions — against a call

Address:	Jaipur, Rajasthan, 302006
Website:	PayTM Mall

I recieved a call through PayTM and they were telling me that there is a scheme that is giving free gifts to the selected users and they told me that you’ve to purchase something till 5000₹ so I did so and they were telling me about my last transactions like what I’ve bought earlier so I want you to call me asap.
Was that call fake or something else?
And if yes then how do they know my last transiction.
I am really very disappointed through PayTM as I used to trust you alot.
So please call me on my no. [protected]
My transaction id Is [protected]
So what the hell is this wrong with it?