"Endued thus with the attributes of Tamas and Rajas, the two Daityas possessed of might and armed with maces, immediately after their birth, began to rove within that vast primeval Lotus. They beheld within it Brahma of immeasurable effulgence, engaged in creating the four Vedas, each endued with the most delightful form. Those two foremost of Asuras, possessed of bodies, beholding the four Vedas, suddenly seized them in the very sight of their Creator. The two mighty Danavas, having seized the eternal Vedas, quickly dived into the ocean of waters which they saw and proceeded to its bottom. Seeing the Vedas forcibly taken away from him, Brahma became filled with grief. Robbed of the Vedas in this way, Brahma then addressed the Supreme Lord in these words."
Here these 2 demons could have stolen vedas from Lord Brahma only if vedas were in written form. But we always says Ved Vyasa first composed them, so does that mean vedas were already present in written form and thus Ved Vyasa wasn't the first person to write them ?