Lost mobile recovered but police is delaying in returning phone back

My phone was lost at Delhi railway station in August 2016. received a call from police 15 days ago that my phone has been recovered from thieves. submit a copy of FIR. i submitted the copy but now they are saying that we have recovered 74 phones from theives so when we will receive FIR copy of all 74 phones, then we will request release order from court and return it back to you as we will not do proceedings for 4-5 phones. What can i do as it may take 2-3 months to submit FIR copies by others, moreover some people will not do the same for a phone worth 7-8k as its market price may be hardly 2-3k and condition of phone may not be that mich good.. How is it justified that they are doing so. What can i do ???