You're leaving out beneficial mutations such as duplications, which voids your math and conclusions.
Assuming there WAS such a thing in the world (there isn't) as a beneficial mutation, then to get past the Haldane dilemma you'd have to be substituting very large numbers of beneficial mutations into the population on a continual basis.
In other words, you'd need to get God to suspend the laws of probability for your benefit. The problem is that the overwhelming bulk of mutations are harmful or fatal and that substituting large numbers of mutations into a population of animals will destroy it. The short version of the dilemma I noted involves one beneficial mutation per generation being substituted into the population which is wildly beyond anything that could ever happen in real life. Haldane himself came to a number sort of like 300 generations to substitute one mutation into any sizable population of creatures and that's without the population being scattered across continents. That's where the talk of quadrillions of years comes from.
You could take something like a fruit fly and by turning on some genes, turning off others, bypassing some (for later), and short circuiting others into working with yet a different gene to make a totally new protein or enzyme, and show up with an Elephant or an Eggplant.
All you need is time and patience, as well as a really in-depth understanding of how each gene works, how the DNA sequences within a chromosome can be made to work with each other, and a whole lot of other stuff we can only now begin to imagine.
It was the first inklings of "epigenetics" that led me to the wholly uninformed conclusion that LIFE was so incredibly complex that somewhere in the body of the DNA strands there must be something akin to quantum level super computers and we'd eventually find them ~ and, oh BTW, that'd make LIFE so complex that it must certainly have originated BILLIONS of universes ago ~ a mere 13.0 billion years just isn't enough for that sort of thing.