在应用内购买，如何在购买后提供消耗品

I am trying to implement IAPs in one app and I'm almost there but still facing some problems. I already posted another question before of this because I found an incomplete tutorial that was missing something so I was stuck and someone already helped me out with that... but in that tutorial they were using a table while I just want to use normal buttons. Between various answers there was an answer that gave me a new way to approach this matter.. so I am giving it a try but here comes the problems I found:I am trying to implement IAPs in one app and I'