It is not uncommon to find a term in an agreement granting certain banking facility that goes along the line that any statement or certificate signed by an officer of the bank shall be the conclusive proof of the amount outstanding under the facility. This term is called the conclusive evidence clause.
Malaysia practices dual legal system, generally categorized as civil law (a misnomer, I personally think it should called secular law as “civil law” refers to another type of legal system in the world) and Islamic law.
When you received a Writ and Statement of Claim, it basically means someone has sued you (let’s call him the “Plaintiff”). You have 14 days to enter your appearance i.e. to tell the court and the Plaintiff that you will be coming to court to fight the suit.