Contract – Loan – Promissory Notes – Whether loan repaid – Whether interest rate agreed – Whether documentation created a sham transaction – Whether illegality tainted contract – Whether evidence admissible – Stamp Duty Act – Whether documents improperly stamped – Whether late stamping permissible – Whether equitable mortgage created – Hearsay objections to witness statement – Failure to take objections at case management – Whether trial judge has discretion to refuse to entertain late application – Whether self-serving evidence of communication to a third party admissible – Whether trial judge has a discretion to exclude documentary evidence which was deliberately not disclosed.