ITunes purchase issue

I purchased something on itunes but it was showing pending on my purchased history which i believe the reason why i can’t download anything on my appstore. So i called my carrier they said everything was fine with my bill everything was up to date. I even tried changing my payment methods but it didn’t work. The error was the previous payment was declined by your carrier. I keep calling my carrier but can’t get any help from them! Is there any other way for me to pay that purchase i made?