whenever there is an LC involved, there will be a bank involved and invariably the Original Bill of Lading will be consigned To order of XYZ Bank.. Your role as a Shipper is to export the goods as per the contract, prepare the documentation as per the LC requirement and submit to the bank, which you have done in this case..
There is no limitation on number of original bills of lading issued.. In your case, 3 originals have been issued..
Irrespective of number of bills of lading issued, if a Negotiable bill of lading has been issued, upon surrender of 1 duly discharged original bill of lading to the shipping line/agent at destination in exchange for the good or delivery order, all other bills of lading issued will be considered null and void.. 
So in your case, all 3 originals have been sent to the bank, but your customer at destination is requesting for an Express Release message for the release of the goods.. As this shipment is covered by an LC and the bill of lading that is issued is a negotiable bill of lading, it is NOT POSSIBLE for the shipping line to issue an Express Release for the same.. The shipping line has fulfilled its obligation..
Its between the Issuing bank and Confirming bank to discuss between themselves the reasons for the delay in the release of the Original Bills of Lading and arrange for at least one of those originals to be surrendered to the shipping line/agent at destination for the release of the cargo..
