Suggest try to speak to another CS to verify if its true.
You wouldn't want to be charged for ST's eSIM charges.
https://www.singtel.com/personal/mobile/services/postpaid-esim
"You can buy a Singtel eSIM online! Simply choose your desired
phone plan and select "eSIM" as the SIM type during checkout.
If this is your first time getting an eSIM with us (new number, port-in, recontract), we’re waiving the fee as a token of our appreciation.
If your contract has not ended but you want to switch to an eSIM, this will incur a nominal fee of $10.90.