Can argos necklaces be refunded?

i bought a heart pendant 9 ct gold necklace. i was wondering if it can be refunded because i want to get my girlfriend something else. argos said they don't refund earrings, foot spas and dental products (they said some items like this.... necklace is jewelery, like earrings) have you ever refunded a necklace or something... if you have tell me please. thanks!