He continued to eat till the Iqamah for Fajr Prayer was being pronounced

A: You have to make up for the day on which you ate and drank while the Iqamah of the Fajr (Dawn) Prayer was being pronounced, as you ate and drank during daylight while you should have asked and been careful, but you did not. Allah (Glorified and Exalted be He) says: ...and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night), then complete your Saum (fast) till the nightfall. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.