Dam009: No it was not updated - yes, it is amusingly outdated. If I remember correctly, they upped it in Australia to $500, and removed it altogether in the U.K.
Norfbank: this is covered by Commercial Law not Contract Law per se.
Whether there was or was not a contract is irrelevant, because even if there were, it was not binding because of the Sale of Goods Act as outlined above.
The only other question that arises is the liability of the sales assistant regarding a breach of warranty of authority, as he was acting as agent on behalf of the company. Not too sure regarding quantum in this, or whether one would actly want to start threatening the poor guy/girl with legal stuff.