JPMorgan Chase & Co. Credit Card Complaint

JPMorgan Chase & Co. Credit card department,

Rewards Maryland

I applied for a chase freedom credit card ( about 6 months ago ) under a promotion where they were offering a $200.00 bonus if you spent $500.00 or more within the first 3 months. I fullfilled my obligation for receiving the $200.00 bonus, however, Chase refuses to give me the full bonus. They say the $200.00 promotion was no longer valid, even though the $200.00 promotion was still available online and at no point when I opened the account did they tell me the promotion was invalid or had expired. I have tried to resolve the issue with Chase by sending them - letters ( -/-/- & -/-/- ), along with a copy of the promotion I applied to. I feel Chase should honor the promotion I applied to and credit my account the remaining $100.00 bonus it owes me.