Product: Credit card or prepaid card

On Thursday, XX/XX/XXXX, I received an email from American Express titled " Announcing something extra for your Hilton Honors American Express Surpass Card '' ( Attached ). The email went on to outline that between the date of the email and XX/XX/XXXX card members would earn 12x Hilton points per dollar spent at U.S Supermarkets. I, along with additional cardholders on my account, spent at U.S Supermarkets during the promotion period. During this time, there was no indication from American Express that these purchases wouldn't earn points. All purchases were in compliance with the terms and conditions outlined in the Amex terms of this promotion that state : " Eligible purchases can be made by the Basic Card Member and any Additional Card Members on a single Card account. Eligible purchases are purchases for goods and services minus returns and other credits. Eligible purchases do NOT include fees or interest charges, balance transfers, cash advances, purchases of travelers checks, person-to-person payments, the purchase or reloading of prepaid cards, and purchases of other cash equivalents. Additional terms and restrictions apply. Points received from your Card will be posted to your Hilton Honors member account up to 12 weeks after the end of each month. '' Furthermore, all purchases in my American Express account showed that they had earned the 12x points and these purchases were also reflected on my monthly statements as earning points under the promotion. When points were not deposited at the end of the promotion period, I called American Express and was reminded of the 12 week deposit period outlined in the promotion. It was not until over a month later on XX/XX/XXXX that I received a letter from American Express stating that all transactions made during this promotional period would not earn points ( See attached letter ). The letter stated the same terms outlined in the original offer ( which I was in compliance with and are the same as the cardholder agreement ). This was the only correspondence that I had received from American Express, nearly 4 months since the start of the promotion and only after purchases on the card continued being made ( giving American Express the associated swipe fees with each transaction ). Shortly after receiving this letter, I chatted with an American Express representative regarding the letter. She reviewed my account and also did not see any ineligible transactions that would keep me from earning points ( See 2 attached screenshots ). On XX/XX/XXXX, she opened a case to look into the reasons behind these letters ( Reference # XXXX ). Presumably in response to this chat, I received an additional letter in the mail ( See attached XX/XX/XXXX letter XXXX restating what the XX/XX/XXXX letter said with the renewed warning that I had 30 days to reach out or the case would be closed. Upon receiving each of these letters I called American Express and agents did not know why these letters were sent but assured me that my case was open and had a closing date of XX/XX/XXXX. However, I was told that cases were usually resolved much sooner than that date. After each of these phone calls, I received duplicate letters, all like the previous ones. Subsequent status phone calls were made in regard to the case. The dates of these calls were : XX/XX/XXXX at XXXX XXXX  CST, XX/XX/XXXX at XXXX XXXX  CST, and XX/XX/XXXX at XXXX XXXX  CST. On XX/XX/XXXX, I received my final letter ( Attached dated XX/XX/XXXX ) stating the exact same thing that previous letters stated and that the case was closed ( Case # : XXXX ). Amex restated the terms of the offer ( which I complied with and previous agents said as well XXXX and that I would not be awarded points for any purchases made during this period. I want to say, which was reiterated to every agent I spoke with, that prior to this incident I have never had a problem with American Express. I have been a happy card holder for many years and have always dealt with caring and professional people at all times I have called, including this incident. Unfortunately, I am disappointed that American Express would make what appears to be a bad-faith effort to encourage spending on their cards, collecting swipe fees in the process and only after, not award points that were made in accordance with the terms of the offer. Furthermore, American Express closed a previous complaint based on a technicality and said they were looking into it, only to have it closed on the same day. I have also asked for the specific reason/specific purchases that did not meet the terms of this offer and in a letter dated XX/XX/XXXX, American Express closed that request with the same generic letter that was sent previously ( Case # : XXXX ). These actions indicate that American Express had no intention of honoring the original offer terms however continued to use the offer as a way to generate spending on their cards. This has been an incredibly frustrating situation.