Whirlpool India — Air conditioner split

My whirlpool ac is not cooling.I asked the local whirlpool about the problem.
Even if i have the AMC, why the technician is asking money for Charging the gas??for doing the leak test, he says he will use Nitrogen, and the customer has to pay for nitrogen etc also.what the heck.
this is totally unacceptable from a brand like whirlpool as your website claims that no charge for gas charging under AMC??but the technician is saying otherwise.dissappointed.please clarify.
vivek, [protected]