Amex Credit Card Complaint

Amex Credit card department,

Advertising and marketing Florida

I received an offer in the mail from American Express for $250.00 Cash Back after spending $1000.00 on the card within 90 days to apply for the - card. Offer expired -/-/2016. I applied -/-/2016 ; was approved - spent over $1000.00. I received credit of $100.00. I have the offer which does n't state anywhere a code needed to be entered. I do n't rememer there being a field or asking for a code. I 'm told by AmEx customer service they would have pre-filled in a code. My complaint is this is deceptive advertising making me believe that since I was applying for the card described on the letter in my name I would receive $250.00. Deceptive as I was n't told on the letter I needed to enter a code - and in addition not being asked for a code. I 'm told by AmEx they ca n't change the promo - nothing can be done. I plan to file a legal complaint, if they do n't honor their advertising.