Writ of certiorari. Upon filing of a land use appeal, the prothonotary or Clerk shall forthwith send the Borough Council, Board or agency whose decision or action has been appealed, by registered or certified mail, the copy of the land use appeal notice, together with a writ of certiorari commanding said Borough Council, Board or agency, within 20 days after receipt thereof, to certify to the court its entire record in the matter in which the land use appeal has been taken or a true and complete copy thereof, including any transcript of testimony in existence and available to the Borough Council, Board or agency at the time it received the writ of certiorari.