It all went wrong when you said ‘I assumed’.
Unless you have something in writing from your company, unless you have any proof that your company took tax off you to pay Norway and didn’t, you haven’t paid them anything.
The Norwegian authorities are quite good at dealing with enquiries however if you peer then tax then they will have no sympathy that your company was supposed to have sorted it.
You may be worthwhile speaking to tax advisor who is knowledgeable in Norwegian tax.
If you do have to pay tax to Norway and have already paid UK tax on the same earnings, you would be able to get your UK tax back under double taxation rules, you don’t have to pay tax on the same money in two places.