IA admissible without WS for misjoinder of party objection?

In DRT proceeding a bank to collect money Lent to borrower from builder to whom amount was disbursed, files OA without borrowers address and includes builder as defendant with address. Defamation as tactic to collect money. Objection to registrar to dismiss was made. Only PO to decide he says permits substituted service. Averment clearly shows d1d2 borrowers and d3 was paid on behalf of them. PO without passing order on IA posts case for evidence. While asked says WS must befiled. Refused to pass orders States we will get stay. Bank write defamatory remarks like defrauding by colluding with borrower d1d2 and says sec 70 contract Act applies. Whether WS a must? Shouldn't IA be disposed? Better to go for reference or Writ or both?