Received an item you did not order?
You are not obligated to pay for items you did not order. However, inform the trader that you do not intend to pay should you receive a payment claim.
Inform the trader in writing that there is no purchase agreement/contract, and that if they choose to uphold their claim it is their responsibility to prove the existence of such an agreement.
The trader cannot demand that you return the item. The trader should in any case pay for the return.
If a claim is sent to a collection agency, it is equally important to contest the claim made by the collection agency. Debt collection agencies should not deal with debts once they become disputed.
Won an unknown competition?
In lottery scams you will often be notified that you have won a large price, but to receive it you will have to transfer a sum of money.
Økokrim (The National Aythority for Investigation and Prosecution og Economic ans Environmental Crime) warns against responding to such requests.
Some companies can also call you. Remember, if it sounds too good to be true, it usually is! Do not engage.
The Consumer Authority keeps track of fraudulent online shops. You can find their list here.