Sky mart - Wrong parcel

I got a call from sky mart who said I've won some contest held by them and new Samsung j* prime mobile at reduced rate of **** rs. On */**/**** got a call from the post office my parcel arrived. Paid **** rs opened the parcel instead mobile i got some gift articles. Called their customer service they said by mistake it got misplaced. I was annoyed said either give the money back or the above said product. Now when called not responding.