is there a link. don't click on it. if it is just a message and also does not ask for a reply then maybe it is real. the wording you use though 'thanking me for pay my bill on time and I am getting a free iPhone 11' sounds ludicrous. i paid my bill but have had no offers of iphones. it reminds me of a sky scam from a few years ago. someone was promised a car if they paid upfront for a year as a thank you.