Citibank Credit Card Complaint

Citibank Credit card department,

Advertising and marketing Arizona

On - - I applied for a Citibank - - - with a - bonus miles award after spending $3000.00 during the first 3 months I have spend more than $13000.00 during those 3 months however Citibank refuses to honor the bonus miles award claiming that the promotion is valid for new customers only. However there is no indication on the website about that : - I have had a Citibank - Credit Card before but it was cancelled in 2015. Thank you