The incentive was for people who ordered a car from inventory. Even though you got a text by mistake, you didn't get it because the car was not from inventory.
Tesla offers 1 year of free Supercharging for inventory cars in end-of-quarter push - Electrek
I’ve yet to receive my free year Supercharging as well. I live in Texas and Tesla can’t sell here legally. I had to have financing in place before they could bring my car into the state. I took delivery on the last day of the month. I’ve gotten different replies and excuses for the delay.
Today I decided to take it to top or at least as close as I can. I sent an email to the Board or Directors asking if was just deceptive advertising or bad customer service. Maybe I’ll get a reaction before I take my next step.