error buy coins

Does anyone know this error? I can not buy coins.It said error : "contact iTunes Store Support to complete this transaction".

smething wrong with your payement type probably, or your security questions need updated

as those tips mentioned,you really need to contact itunes support for more info
about the purchase

I also encounter the same error message. I tried to purchase in-game items from a different game and it was successful so I guess my payment type is all fine. Any other ideas why this is happening? Thank you.

Try waiting a day or so and trying it again.
I had this before as well and I waited a day and it went okay.

Also, if you are using cards, try re-entering the details.
Log in, remove the details, log out, log in and enter the details again

Good luck!
If the above doesn't work, contact Apple. ^^