can the mvd be used for online transactions for local companies such as booking hotel in genting and buying flight tickets frm air asia?anyone used their mvd for the above 2 transactions?do i need to get a pin?

i used my mvd card to pour petrol then the transaction was cancelled the first time coz my smiles card couldnt b detected..then i did the process again but when i checked my account they have debited it twice!! what should i do?anyone experienced this before...