Monthly charges increased in error after automated plan change promised at no additional cost
On Tuesday, June 16, 2020, I received a text message from AT&T at 7535 stating:
AT&T Free Msg: Great news! As a valued AT&T Signature customer, your plan has been upgraded to Unlimited Elite at no additional cost. Your new plan has free HBO Max, 30GB of mobile hotspot per line, HD streaming and more. Learn more at att.com/signatureextratoelite
My previous plan was AT&T Unlimited Extra(SM) at $80.00/month; now it is AT&T Unlimited Elite(SM) at $100.00/month. I don't consider an additional $20.00/month "no additional cost." How do I dispute this?