Downgraded plan

Good day Firstly I want to thank you guys for the great service of the last couple on years as I'm an loyal customer of Telkom mobile for a few years now and loved the data plan I was on, which is the R70, 500mb data, 2gb of whatsapp data, 50sms and 3000min telkom to telkom minutes. I got a message a few months ago that it is time to upgrade my device. I chose the Samsung A72, I love the device, thank you very much. The thing that I'm not happy with is the downgrade in data plan. Why can't I stay on my data plan that I'm happy with, that I love. Can I please stay on my previous plan? It was done a previous time, why not now?