iTunes purchases
I purchased music about 5 years ago and it won’t let me download the songs onto my phone, despite saying purchased in iTunes.
iPhone X
Contact the Apple Store Support about this and request to speak to an Apple advisor about regaining access to these purchased items. Sometimes items are removed from the Apple Store and are no longer accessible. That’s how it is :(
So, give Apple Store Support a call and request assistance. They’ll know what’s going on.
Contacting Apple
USA: 1(800)MY-APPLE