Since you didn't mention a lot of relevant factors, I really wonder if you know what it takes to get accepted by a top school, especially one like Harvard.
1) If that's all you have to show, probably not. A lot of applicants have great GPAs, MBAs, GMAT scores, etc., etc. Those things can help you to get an initial positive reaction, but they are not enough to be admitted. You need something that makes you stand out even among amazing applicants from all over the world. And I don't see anything close to that.
2) I often recommend taking both the GRE and the GMAT, and use your strongest result for applications.
3) Work experience is usually not really relevant for PhD applications, so I don't think working a few years in general management would make much of a difference.
4) You're already doing an MBA. Why go for another one? If you want to do something before applying to a PhD, at least do something that is going to be more helpful.
A PhD is focused on research. And your profile seems to be really lacking on that regard. So, that's where you should really improve if you want to apply to a top university.
I may be wrong, but right now, it seems that you have no research experience, no research papers, no letters of recommendation from researchers with a good reputation, no degree with a focus on research (an MBA is typically more of a professional degree, not research-oriented). Why would Harvard choose one, instead of another applicant that has all of that?