is there any stores in Australia i can find a roblox gift card i would really love one but Ive got know idea about where you can buy them?

i brought one once online but it was a complete rip off i got to play it for an hour and then it logged me off and wouldn't let me back on and didnt even give me my $10 back so i don't wont to get one online again defiantly not i would like to have the card and the receipt if it rips me of again but i really want builders club and get robux