PAVOI14K Gold Plated Crystal Solitaire 1.5 Carat (7.3mm) Cubic Zirconia Dainty Choker Necklace | Gold Necklaces for Women

Is this necklace rose gold like the bracelet?

What is under the gold plating? Is it 925 Silver or tin or some "alloy"?

Do we get certificate that it is real Swarovski crystal with 14K white Gold plating?

I bought this one as a birthday gift to my daughter. The gem is fall out after she wears for two days. Can we return it (not new anymore)?