When I try to buy PokeCoins in Pokémon go the logo spins but never stops and no error message pops

Hi romain160,

It seems you're having trouble completing a purchase in an app and we can help.

Try forcing the app to close and restarting your iPhone:

How to force an app to close on your iPhone, iPad, or iPod touch - Apple Support

Restart your iPhone - Apple Support

Then follow along here:

Buy additional app features with in-app purchases and subscriptions - Apple Support

If your payment method is declined in the App Store or iTunes Store - Apple Support

Let us know if that helps.

Thanks for using the Apple Support Communities.

Some other things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.

Try a forced restart.

Reset Device.      

If necessary

Hard reset.        

Do a backup and try a factory reset. Then restore from your backup.

Restore to Factory setting.      

Backup - Restore your device from an iCloud or iTunes backup.