sounds like online gaming platform.
and your card probably has been saved into your google account.
never used this particular card before with google

if you did not make the transaction... as of now.. you should have:

changed your google password to something more complex.
contact google support to refund..
yup. did that

your card is still safe so no worries.

i got the same problem last friday..received an sms for two transaction charge to my credit card from google services rm4.00 & rm30.60..i never use that card for any app purchases...i'm using an iphone and i'm using a different credit card for app store.. immediately call the bank informed them i did not initiate the purchase.. they confirm my card was charge..suspect a credit card fraudster or hacker..the card was canceled immediately and ask me to fill in a dispute form..will receive new card in 5 days time..

I was charged RM399, called cc and they cancelled and replaced the card. They investigate on the transaction also, in which they reimburse back in next statement.