CGA B2B contract-out needs to be *in writing* IIRC. So unless you actually signed something up-front or they specifically sent terms and asked you to agree to them, it's still covered by the CGA. And if you do that, you've probably got a contract covering hourly rate and supply markup.
From Consumer Protection:
- you as the buyer and the seller are in trade and agree to this
- the agreement is in writing
- it is fair and reasonable to do so.
B2B transactions are considerably more complex than B2C transactions as the buyer is considered to have significantly more knowledge than a consumer. As such you need to review the entirety of the correspondence.
The battle of the forms, where each party attempts to conclude the transaction on its own conditions, is a particularly tricky one. In some circumstances “first shot” wins, in others “last shot” wins.
It’s why it’s always better to actually have an agreed contract rather than a morass of deemed acceptance.