You may submit a complain in person in one of our shops or via mail:
303 Avenue, Mokotowska street 40/3, Warsaw.

When submitting complaint in person, you must provide a defective product along with the proof of purchase and completed complaint form to one of the 303 Avenue shops of your choice.
(you can find one here)
In case of lack of receipt, provide a bank transfer confirmation that confirm the purchase of the product.

When submitting complaint via mail, send a defective product along with a completed complaint form to the address 303 Avenue Sp. z o.o., Mokotowska street 40/3, 00-543 Warsaw.

Sample form to download:

LETTER OF COMPLAINT

303 Avenue will resolve your complaint within 14 dni of its receiving.
Detailed term of use can be found here.