Question about Gigabyte X570 I Aorus Pro WIFI

On January 13th, I bought the motherboard and Ryzen 5 3600 for the offer Gigabyte Aorus had for 50 EUR cash back. The Aorus offer was ending 15th of January but I received the products today, January 16th, and there is nothing in the Aorus website anymore to register the products and get the cash back even though I bough the product 2 days before the deadline. Should I contact directly Gigabyte or you have any contact / web link I can use to benefit from the offer? Thank you.