Kolkata Foreign Post Office — non-delivery of parcel even after responding to show cause notice

Address:

The Appraiser of Customs, Postal Appraising Department12, K.S. Roy Road, Kolkata, Kolkata, West Bengal

My international parcel from uk with tracking number ea[protected]nl has been detained by customs since 24th dec 2018. I received the show cause notice asking for invoice and bank transaction proof in january first week, which were duly mailed via speedpost (Ee[protected]in) to the postal appraising department, k. S roy road kolkata and delivered on 14th january.
On 16th feb, i was able to talk to a foreign post office employee at this number[protected]It was provided in the show cause notice) and was informed that my parcel will be released in a few days. Been trying the same number everyday for the past two weeks but no one answers the phone.