The lack of evidence is actual evidence. In the case of evolution, the lack of a fossil record of transitional forms is actual evidence that transitional forms did not and do not exist.
First of all, lack of evidence for a thing's existence does not equal evidence that said thing never existed. That's just nonsense.
Second, the fossil record does contain evidence of transitional forms. Archaeopteryx is a transitional form. Hylonomus is a transitional form. There are others - a simple Google search will bring up dozens more, if you're at all interested in seeing the evidence.
While it is true that the fossil record does not show every single transitional form, it is a falsehood to claim that the fossil record lacks transitional forms entirely.
Which life-forms, that exist today, do you think are transitional?
How about whales? They have vestigal leg bones. There are species of cave salamanders with regressed eyes that lack the apparatus to see. Pythons and boa constrictors have vestigal pelvic bones. How's that for starters?
Using your logic, the fact that there are no unicorns that exist today is not evidence they never existed.
As Rush would say, this is using absurdity to expose the absurd.