False advertising

I app**** for an account at Cross trainer in Brooklyn in August 2019 and promised to get 20% discount on my 1st purchase and the person who was in charge that day said they don't have vouchers they will call me the next day to get my discount.

They phoned me and when I get there they said RCS said the discount will appear on my next statement, that didn't happen then I phoned RCS which they said that was supposed to be done at the store. I have been making calls to the store with no updates.

Please let me know if this was a false adverti*****t or what.