here is the case:
i buy one top up card rm30..n i carelessly left the card unprotected on my table. when i try to top up using the number on the card, it can't be used anymore. i suspect there is someone who's already used the number. however i have the card with me. that's mean i got the top up number n serial number with me.
so i'll like to ask, if there is anyway that will 'block' the usage of the top up card rm30 from being used anymore. that's mean the rm30 will 'burn' from whoever the person used my top up number.
another thing, will it be possible to trace the phone number that used my top up card number?
thanx in advance

yup..i scratched it..n then i got some emergency..went out only about 15 minutes..left the top up card on the table..never expected that this will happen :-(