SkyKing — courier sent from kolkata on 20.07.17 to new delhi & today is 27.07.17 & courier not recd yet

We have sent courier through sky king courier vide their consignment note no.[protected] dt. 20.07.2017 & still courier not delivered to consignee. Online tracking shows that courier lying at their mahipalpur office. Yesterday when consignee called to their mahipalpur office, they said that they don't have any courier against this number & asked to contact origin office. Today their kolkata office told me that courier will be delivered today evening. Courier contains some important document & because of this delay, we are very much upset. Please do the needful