Pages, Numbers and Keynote = £7.99??

I know there's been previous discussion of something similar, but my version of the problem doesn't seem to have occurred before. Pages, Numbers and Keynote are appearing at a cost of £7.99 each: during the initial install they were offered for free.

I think the reason for this error is tied to how the iPad was set up;

I work for a company, and we've just rolled out iPads to our department. When we gave the iPads out, we went round and did training sessions on how to set them up and use them. One colleague was struggling to log into his Apple account to download the apps we use. To help him out, someone else logged into his iPad so he could download the apps and follow the rest of the training. When the apps updated he was asked for the password for theApple ID of the person who logged in for him.

The solution he applied was to delete the apps that were downloaded with the other Apple ID, log in with his own Apple ID, and download them again. Once he deleted those apps and logged in as himself, they appeared in the app store for £7.99.

The iPad is brand new, iPad Air 2, 128 gb, 4G.

On the advice of other people who have had a similar problem, I have tried logging out of the Apple ID and logging in again, closing all open windows and clearing the cache in Safari. I’ve also done a factory reset, but that doesn’t solve the problem.