What is the maximum time period between how long a service was provided and a bill is received?

I did some business over 17 months ago (August 2003) with a Canadian company and I thought I had paid everything for, but now they sent me a rather large 'secondary' bill.

Apparently the bill is legitimate but I'm wondering about the timeline factor.
I know that in traffic court they have a certain time period of 'due diligence' to process the ticket otherwise it can be dismissed, I'm just wondering if there is something similar within Canadian consumer law.