Product: Credit card or prepaid card

On approximately XX/XX/XXXX, I was approached by Citibank to add to my charge account of some 33 years the benefit of double cash back on select items only. I honestly do not remember if this was by mail or email, but Citibank customer service advises me that I responded by email. This is odd to me as I thought I had opted out of their emails many months ago, and in fact show my last received email in XX/XX/XXXX and did not receive another email from them until I received my first double cash back statement in XX/XX/XXXX. Perhaps you can verify whether I did indeed opt out. I do however remember initiating the process to add double cash back ( on selected items only ) to my account. I have had several other banks make me this offer and have done so without incident. When I paid this years XXXX statement, I happened to look at my rewards points balance and noticed it was only around XXXX points. Before I made the change to double cash back, my rewards point balance was around XXXX points. Thinking there was an error, I called their Rewards Point Dept., and was informed that the balance of XXXX points shown on my statement was correct. They also confirmed that I did indeed have some XXXX points before the conversion. Evidently, in the fine print that I supposedly agreed to, there was a clause that read " all previous unused rewards points would expire in 60 days ''. Obviously, I was upset and not satisfied with this answer and asked what recourse I had. I was informed that I could contact Citibank customer service and was given their phone number. 
After speaking with customer service, I was told the same thing that Rewards Service told me. I then asked to speak to a manager. I was transferred to a supervisor by the name of XXXX. He said he was not allowed to give me his last name. He told me the exact same thing that the others had told me. That I did have XXXX points and they expired on XX/XX/XXXX, 60 days after the account change. He further explained that I did do this online and that when I hit the " I agree '' button, that the point forfeiture information was included in what I agreed to, so that as far as they were concerned, I did indeed agree to it and there was absolutely nothing that could be done about it. I told him that I wanted to file a formal protest and was grudgingly told that I could write to Thank You Rewards, XXXX XXXX XXXXXXXX, XXXX XXXX SD XXXX, but that it would not do any good. Incidentally, XXXX told me on three different occasions that my protest would be a waste of time and not do any good. So, I am doing this instead! 
As a senior citizen, and somewhat elderly, I feel very taken advantage of and maybe even a little discriminated against. My mind is just not as sharp as it used to be, and the supplied information was confusing to me. I believe that this was intentional on Citibank 's part, and that any normal person of my age would have found it confusing, ambiguous, and misleading. I would be very interested to know if my age group was targeted by CitiBank in what I can only think of as a stealth scam. 
My wife and I are on a semi fixed income and it had taken us decades to collect those points. There is no way that increasing my rewards points on selected items only, would ever come remotely close to the XXXX points ( {$850.00} ) that was taken from us. That is a lot of money to us and it was part of our small nest egg. As the old saying goes, " I may be ignorant, but I'm not stupid '', and I would never have knowingly agreed to this ridiculous proposition. Amazingly, Citibank allows you to directly convert your points to pay or credit your account. At the very least, they could have just rolled my points over as a payment or credit on my changed account. I truly believe Citibank was being intentionally deceptive and dishonest, or rolling my points over would have been the obvious solution. Also, on XX/XX/XXXX, I received a " Confirmation of Account Change '' letter ( attached ). Nowhere in the letter nor the two accompanying brochures was forfeiture of unused previous points mentioned, nor did I reveive any other notices of impending rewards point forfeiture. In my opinion, this is the absolute personification of intentional omission. 
I can not help but ask myself who was benefited by this account change. It certainly was not in my ( the customers ) best interest but seems to have greatly benefited Citibank. And just to add insult to injury, I just received another letter from Citibank ( attached ) informing me that as of XX/XX/XXXX, they are removing some of the promised benefits attached to this card, ... Roadside Assistance, Car Rental Insurance, Citi Price Rewind ( dropping from maximum of {$2500.00} to {$1000.00} per year ) etc. I am however convinced that their " fine print '' allowed them to do this and that I agreed to that also. 
Here 's the bottom line, ... I was told that my account number would stay the same, and I didnt even realize that I was doing anything but adding a benefit to my current account. At least that is how it was represented and how I interpreted it. If I had been aware that I was signing up for a totally new and different type of account that could result in the forfeiture of decades of earned rewards points, I certainly would have been more cautious and diligent, and most probably, not even considered it. 
Thank you in advance for you time and consideration regarding this matter and anything you can do to help me resolve this issue would be greatly appreciated. If there are further questions, concerns, or additional information is required, please advise