Get the service manager to show you the service manual, it has all of this written in plain language. Show him that and ask him why is this not followed. If he says its OK as it is - then get this in writing on the showroom letterhead, stamped and signed by him, then send a copy to the local agents like IMC, AHL, PS etc and demand a proper answer.
The letter should detail what is used instead of the manual recommendation.
Trust me - in Pakistan every employee at any place wants to act like he's king, to get any work out of them I always press to get whatever they are saying on paper or atleast as voice recording if they dont want to give it on paper - denial of such means that they are doing wrong and they know it.
You cannot do this on "jay dee amm" aka pikachu aka pokemon cars from Japan Auctions as no one is their authorised agents no matter if they say Toyota, Honda or even Suzuki on them.