Rules of Civil Procedure 500-510 (Part V) govern cases filed on or after August 31, 2013, and cases pending on August 31, 2013, except to the extent that in the opinion of the court their application in a case pending on August 31, 2013, would not be feasible or would work injustice, in which event to formerly applicable procedure applies. An Action taken before August 31, 2013, in a case pending on August 31, 2013, that was done pursuant to any previously applicable procedure must be treated as valid. Where citation or other process was issued or served prior to August 31, 2013, in compliance with any previously applicable procedure, the party served has the time provided for under the previously applicable procedure to answer or otherwise respond.