Telus and Koodo are treated as separate entities within the company. Telus reps likely can't see the usage on your Koodo account. Additionally, are you sure it was really Telus that called? Telus rarely does outbound calls to sell services. There have been a few scammers lately pretending to be Telus.
This is accurate.
Koodo, while a subsidiary of TELUS, is operationally separate especially at the customer support level. TELUS reps will not automatically have visibility into Koodo accounts and vice versa.
You're also right about the spate of scammers who are fraudulently purporting to represent TELUS (and other companies).