Telstra mobile plan small $55 Clearance

Product Name: Telstra mobile plan small $55 Clearance
Is this even legal? Telstra automatically upgrading me to a more expensive plan without asking. Currently paying $39 month-to-month ($10 monthly discount at signup) for 15gb. : r/AusFinance Clearance, Telstra increases mobile plan pricing for new and existing customers - Tech Guide Clearance, SIM Only Plans from Telstra Clearance, Is this even legal? Telstra automatically upgrading me to a more expensive plan without asking. Currently paying $39 month-to-month ($10 monthly discount at signup) for 15gb. : r/AusFinance Clearance, Telstra Reveal Revamped Phone Plans - Clearance.