Can’t switch to better promo deal 1 month after getting home internet.

Over 18 years of loyalty, and I got coaxed into getting the home internet.  Purchased it October 4, 2023 only to find they came out with a better promo (LESS monthly payment + 50" TV) but they say oh well too bad so sad "sweetie".  So I'm supposed to pay more a month than someone who waited to sign up. Why not just let a customer cancel and come BACK to get the deal and you KEEP a customers business?  Instead I was offered to cancel my ENTIRE family plan and go elsewhere.  Well done TMobile.  Well done