Roblox

Hello , so i play a game and it’s called roblox. And there is something called robux and that’s money in roblox that u can buy with ur own money. And today I tried too buy robux but it said ‘’ purchase failed ‘’ and then it said ‘’ please contact iTunes support , so now i wonder if yall maybe could help me , thank you so much for listening and I would be very appreciated if yall could help me out! dear Evie