Wanted: Any freelance IT guys willing to offer your services..?

Hmm.. doesn't look too bad but again I'm no expert on this shit. Ours is quite a bit quicker between hops here.
How many users do you have? Could someone be download large volumes and taking your bandwidth?
Do you have any bandwidth monitoring tools available?

I think you may be right.

I have just spoken with them and apparently in Dec and Jan our usage was up near 50 whatever bytes per month, we only used 10-15 whatever bytes per month previous to this.

They are having a look to see what may have caused this.