[Poppadaddio]

Thanks for the Report

Well, yeah, jeans are lousy for cycling. At least on a bike like that. You need a real kit.
As for the size, usually BD doesn't have 64 cm frames; 62cm is the largest they have listed for this bike on their geometry chart. How big ARE you, anyway? Raise the seat, maybe get a little longer stem, ... It may not be too small at all. But go to a bike fitter -- it doesn't have to be at a bike shop. PAY for the service. Armed with the measurements you need, you should be able to pick out a bike by yourself next time.
BTW, what size crank did it come with?

 

[Poppadaddio]

You are off the charts!

Seriously, as if you didn't know. I'm only 6'2" and I have "issues" with sizes of lots of things (car seats, hats, ...). I'm afraid you need expert help.
Try a pro bike fitter, one who isn't just trying to sell you a bike.
Or in this case, as much as I like Bikes Direct, a local bike shop with access to a much wider range might be a better place to turn.
For sizing that big, I'm afraid you're going to pay.
But what do I know?