1. Donate them to charity. There are charitable organizations that would be very willing to accept your donations.
2. Sell them. Find the organization that sells slightly used items. Since your gifts are new, you can get a fair price for your items. You can use the proceeds to buy the stuff you want.
3. Return them. If you can know the store where the items were bought, you can use your right to return unwanted items. Be sympathetic so that you can get the store’s nod to return the items since you are making the return without the receipt.
Your options are actually endless. You may keep them in your attic or give to someone else. You may use your aesthetic skills to make a new stuff out of your unwanted gifts. Whichever option you choose, there are a lot of good things that can come out of your unwanted gifts.