I know quite a few people who received their first Ph.D. after the age of 30, and some who received their M.D. after the age of 40. Their success hinged on their desire to do the work that comprised their Ph.D. research, or their desire to become medical doctors and perform clinical medical duties. It's not your age that matters as much as your motivation and intention does. However, note that a theoretical Computer Science degree and a Mathematics degree are very different beasts, even if at the base of both lie the same thing in the theory of automata.

And don't even think of lumping Statistics and Mathematics in the same pool -- :) -- without expecting to get some raised eyebrows and arguments. Do you notice that statistical questions on this web site get told to ask the question over at a different website?

You probably need to find your focus first. What do you really want to do: computer science, mathematics, or statistics? Then figure out where you can go to further your specific interests and work with someone else who works in that domain.

What questions are burning in your head? What do you want to figure out and understand better? What is it that you can figure out which no one else could probably do, due to the unique confluence of talents and skills and interests which you possess?