If the product you bought in Slovenia is in perfect condition, the seller is not obliged to exchange it in case you changed your mind. However, many sellers offer this possibility within 8 days from the sale. In such case, you will need to present the respective invoice.
Some sellers also give additional guarantees: e.g. "if you are not fully satisfied with your product, you are entitled to return it and claim reimbursement".
When making a claim, always refer to the general conditions of the sales contract, or inquire in-store. If the trader has mentioned anything concerning exchanges or reimbursement in his advertisements (either in-store or on the invoice or on any other material), they are obliged to respect this.
