You don’t worry about that. It’s just a marketing technique used by those who sell Rudrakshas. The single sided Rudraksha bead is just bigger than the double sided one.
The important thing is that you should be Ek mukhi (one pointed in devotion) .
Never mind whether the Rudraksha you wear has one, or ten, or fifteen faces.
I don’t attach much significance to this and I don’t want you to attach also.
If Rudraksha is good and it does something good for your physiology, then that is enough. If you feel like wearing it, wear it, otherwise it doesn’t matter if you don’t.
Rudrakshas are not a matter of life and death. It is not that if you put a mala (chain) of ten beads you will get enlightened. Even crows sit on the Rudraksha tree, they don’t get enlightened. We have some trees in the ashram.
Yes it has some physiological and energetic effect, but you don’t have to give too much importance to it.