Mobile RP Purchasing Na

Hi I'm a New Zealander. I've been playing on Na nearly all my time on league and I've been to Oceania and back. I've have purchased a lot of RP in my time playing and I'm trying to mobile purchase $5 NZD of RP but it wont send me a confirmation text... I've tried and tried again to get my number right so it isn't that but this is what I do... Shop > Purchase RP > I change the "currently showing payment options for USA" down the bottom to New Zealand > Mobile payment > $5NZD > I enter my number > it says please send a text message to 3542... But it says that I will "receive text message confirmation" but I don't receive any text and I think this is the problem... I want to buy jinx now she's on sale and I just don't have enough RP. Please help I don't have a credit card I can use for purchases and RP cards I buy in NZ don't work on NA Btw I have enough credit for the purchase and my carrier is Spark NZ Thanks nice job on ekko riot