Greetings D-Fiance,
After reviewing your post, it sounds like you are not able to download music from iTunes Match unless you are using Wi-Fi. I would recommend that you read this article, it may be able to help the issue.
Resolve issues with iTunes Match - Apple Support
If you're using an iOS device and aren't on a Wi-Fi network, turn on 3G cellular data for iTunes Match. Fees might be associated with downloading over cellular networks. Contact your wireless carrier for details. Learn how to understand cellular data settings and usage. To turn on cellular data use the steps below:
- Tap Settings > iTunes & App Store.
- Tap the toggle to the right of Use Cellular Data to turn it on.
Thanks for using Apple Support Communities.
Take care