Neither the one-day limit nor the return exclusions apply to products that are faulty or not as described. Report it to customer care; once the fault is confirmed, you can choose between having it repaired, replaced or refunded without paying anything, and repairs take between 7 and 21 working days.
Certain products come with a manufacturer's warranty, and your original invoice copy doubles as the warranty card, which is why you should keep it; accidents, misuse and repairs done outside the authorized workshop aren't covered. The store states that all its products are authentic, and promises a full refund of the price if anything bought there is shown to be counterfeit.
Source: AIGNER Saudi Arabia: store policies (defective products and warranty)