Question about the return of equipment, namely headphones.?

Question

Headphones

On December 7, I bought headphones, Sennheiser cx 200.
They didn’t fit me, because of the high frequencies.
Before buying, the store said that I can return them within 15 days from the date of purchase, but they did not say a word about the packaging.
In this connection, I have questions:
1. Can I return the goods and money, provided that the box is opened, has no presentation?
The store said that they would not accept the goods back, saying that because of the box they would not be able to hang the goods back for sale and they would not accept earplugs due to hygiene either ..
Partly contradict themselves.
2. Who is right in this matter?
3. Which articles of the law should I refer to, if I am right?
Thanks

Answer 1

Would you personally buy obviously used earplugs in a torn, sealed packaging for the price of new ones?
Would you put them in your ears?

Answer 2

By law, you can return the product if it does not fit within 14 days, but
"The exchange of non-food products of good quality is carried out if the specified product has not been in use, its presentation, consumer properties, seals, factory labels, as well as marketable check or cash receipt issued to the consumer along with the sale of the specified product.

Answer 3

The short answer is no, you can't, the law doesn't give you that right.