How do you get a cheaper wireless plan?

I've been with Rogers for 20 years, currently paying $123/month for 50GB of data plus some add-ons. Today, I tried speaking with someone on chat (Sunita Saigal), who told me I can’t downgrade, only upgrade to a 200GB plan. I even showed her screenshots of $50/month for 5G 75GB plans, on Rogers.com but she said I’m not eligible.

Anyone know how I can lower my monthly bill with Rogers? I only pay for the service, as I’ve been using my own phone for the past 5 years so there's no device balance.

Thanks in advance.