Hi guys,would like to ask something about the autopass.

i just came back from Singapore recently.

it was my first time driving into Singapore, thus had to purchase the Autopass CEPAS .

i understand from this thread that it costs $10 for the card ($4 credit and $6 non-refundable)

However, during my visit they charged me $20 for the autopass card ($4credit and $16 idk what cost)

can someone enlighten me on this?is this normal?