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