Amazon India — No Complete refund

I have order one plus tab 3 on 10 oct and supposed to be delivered on 16 oct it has to items including tab and pen in total 48000 something and in sale pen is showing to be free It has to be delivered into parts one pen and other tab I received pen but tab is not been delivered when I asked for refund it is said to to 48000 and after 7 days I got my refund details but they detected around 5000 from me for pen but it is shown to be of 48000 refunded I have talked to customers care they told the deduction is of promotional charges but what what kind for scam is that