There's nothing to worry about with Infacol. The information leaflet even says that an accidental overdose isn't usually harmful, it's a fairly innoccuous medicine, as medicines go. Basically it has an ingredient that makes all the little air bubbles which are stuck in baby's tummy (causing the pain) join up into big air bubbles which then can come up.
It can take a few days for it to work (it's a cumulative effect), so don't be surprised if there isn't an improvement straight away. The other thing to consider is gripe water, if you'd prefer that to infacol.
Hope you find something that helps with your LO's wind soon.