Delhi Police — sarita vihar delhi police not action my fir and not give me fir copy

Address:

New Delhi, Delhi, 110076

Fir no=[protected], my mobile no [protected]
Sir, I see I phone 7+ add on olx.seller said you will pay 18000 rupee through pay to. i payment 18000 but seller not send phone by courier. I also fir in sarita vihar police Station, but sarita vihar police not action this case not give me fir copy why.i also want 8-10 times on police station.
Please action madanpur khadar sarita vihar police si nagendar nagar. Why Delhi police note action fraud case