The Baliffs were unable to execute the warrant because the only address given by the Halifax was a PO Box number. Does anyone know what I should do now? Thanks

Having already successfully claimed (via Moneyclaim) a substantial amount of charges from one Halifax account I thought I'd try and claim back a much smaller amount from my other account. Following exactly the same process as before and recieving the usual rejection letter I went to court. The Halifax did not contest the claim and after 14 days the case was found in my favour. However after the final rejection letter the Halifax haven't communicated with me on this matter. I have now actioned a Request for Warrent of Execution which was issued on the 11th Jan. Basically can someone tell me WHAT HAPPENS NOW? Thanks