That would be like asking why God hasn't disproved the existence of science. Both are the wrong questions to ask.
God cannot disprove the existence of science, because science exists. Science cannot disprove the existence of God, because God exists.
The only way to start dealing with this dilemma is to admit that science simply does not have the means to explore the existence of that which is immaterial and not bound by space-time. Scientific enquiry has its limits, and metaphysics is beyond its legitimate scope.
Yet we can learn both from science and from theology. It really helps if we seek a bigger narrative about life by looking to more than one source for our information. We now know from scientific theories about the origins of the universe and the nature of time that we have to speak of the 'birth of space-time'. We know that both space and time came into existence - not IN time or space, but AS time and space.
This is such a gob-smacking idea, we have to ask, Where were time and space before they came into being? But that is just as mind-blowing as, 'What is the universe expanding into?' Our finite brains cannot compute answers because we must live IN space-time, not outside of it (as it were) as does the One who created space-time for this material universe to operate in.
Only spiritual sources (such as the Bible) inform us that God dwells in eternity, which means 'timelessness'. We cannot grasp what timelessness means. Yet Christianity has always understood that God is outside time; that he creates the universe WITH time, not IN time. God did not stand in space-time and rearrange things that were already there. God is therefore not an object in the world, but One who stands beyond our world. Heaven is a realm beyond the world of space and time that we presently know and inhabit. You might as well ask a two-dimensional person to visualise a three-dimensional object (as C.S. Lewis explained, speaking of 'Flatlanders'.)
This simple illustration shows that we need both science and theology to combine to enable us to escape from a monochrome picture of reality, and to get a broader, more colourful and detailed canvass of life to look at. Points culled from the book below, written by a scientist.
C.S. Lewis 'The Poison of Subjectivism' in 'Essay Collection' p 664 (HarperCollins, London, 2002)
Alister McGrath 'Inventing the Universe - why we can't stop talking about science, faith and God' pp 88-89 (Hodder & Stoughton 2015