SA need undertaking letter to confirm bank loan before they will order your car( dealer is paying first to get the car before bank release money to dealer )
Once dealer confirm bank loan and get undertaking letter frm bank, dealer will order the car, once car arrive with chasis number and engine number thy willbforward the particulars to bank to key in e-hakmilik so car can go register.
Looking at what you said, there should be a miscommunication between banker and sa or maybe someone is pushing blame of delay to another.
Try confirming with your banker had the hire purchase been approved or not. If yes, ask him immidiately forward the letter of undertaking to the dealer.

If thats the case the undertaking letter should be ready. Yes letter of undertaking is necessary because it is a formal letter by the bank to guarantee payment of the car towards the dealer. Example if dealer gt no letter frm the bank, thy use their own money to buy in the car from distributor and later on you forfeit the purchase. The car eould get stuck at their dealership and their money get stuck. So dealer must request undertaking letter from bank before getting the car in. Rlse once registered thn no one wanna pay dealer thry lose money.