Can one repent from masturbating day and night in Ramadan, and how can a person rectify his situation and draw closer to Allah?

The door of repentance is always open, no matter how numerous or repeated the sins. Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" [Az-Zumar:53]. Piety does not mean never falling into sin, but rather repenting from it immediately, as Allah described the pious: "And those who, when they commit an indecency or wrong themselves [by sinning], remember Allah and ask forgiveness for their sins - and who can forgive sins except Allah? - and [who] do not knowingly persist in what they have done." [Al 'Imran:135]. You should always bear these verses in mind to avoid the devil's temptations. And if you fall into sin, make sincere repentance immediately. The Messenger of Allah (peace be upon him) said: "Every son of Adam is a sinner, and the best of sinners are those who repent." (Hasan by Al-Albani). And remember: "Be mindful of Allah wherever you are, and follow a bad deed with a good deed, it will erase it, and deal with people with good manners." (Narrated by Ahmad and At-Tirmidhi). Seek Allah's help through supplication and humility to assist you in getting rid of disobedience.