Unpleasant experience at MIMI.Q cosmetics

I bought eyeLash glue at the store yestaday so when i return it today they tell me they cannot take it back because i used it, i explain to them that i did not open anything it was like that when i bought it and i did not see it as an issue since it was my first time buying it. They were not polite at all as i tried to explain that the product is not even squeezed to be regarded as used, they told me they will not give me my money back nor will the exchange it for the one that i want. i left it there