Nokia Store is charging for the app updates?

Hello there.

I've published one APP (CheckMyMeals) at Nokia Store. One user purchased my app (billing #1), then he updated the phone to Belle Refresh. After that, he can't download the app, since the store is charging him again.
I've realesed some updates (only for the app itself, none for price or anything else). I don't know if he purchased the last version or the first release version but, in case he bought the first release version, is Nokia charging for the updates?

Thank you.

If it is an update to the same piece of content, then the updates should be free (no charge).

Hello, thank you for yout time.

Yes, the update was done only at the app and the Store is charging the user again.
Is there a way to fix it and let the user free of to buy the item again?

Maybe the customer has created a new account/login in Nokia store instead of using his existing account.