Product: Credit card or prepaid card

I have been a Capital One customer for many years. Earlier this year ( XXXX ) I received an advertisement for the Capital One Savor One Card to my personal address with my name on it. On the card, it advertised a spend bonus where, if you charged > {$500.00} to the card in the first 3 months, you would receive a cash back bonus of {$150.00}. Seeing this as a good incentive to open a new credit card ( which I had been searching for ), I went online to Capital One 's website and signed up for the card and was instantly approved. The next month, I paid off a balance of > {$500.00} and awaited the spend bonus to show up in my account. It did not. 

The first time I called Capital One and told them my situation, I was told by a gentleman on the phone that the spend bonus should show up in my account within 2-3 days after the balance was paid off, even though had already been about 2 weeks since I did that. He transferred me to a 'rewards specialist '. The 'specialists ' gave me 4 reasons as to why I was not eligible for the rewards : 1 ) I did not apply for the credit card within the time frame the spend bonus was being offered. When I told him that was not true because I received the ad via mail and that it was still being advertised currently, he gave me another reason. 2 ) I applied for the credit card through a 3rd party website and therefore I was not eligible for the spend bonus. This is not true because I signed up via Capital One 's website as directed by the direct mail I received. 3 ) I was also told that the specific code that came with the mail advertisement did not include the spend bonus. This could not be true because even when going through the application online the bonus was still being advertised to me. ( bait and switch ) 4 ) The final reason they gave as to why I was not eligible was because of some vague wording in fine print stating that previous or existing account holders may not be eligible. I have never held a Savor One account, and, although I was a previous Capital One Customer, it did not say the offer, which I personally received from them, was not available to existing Capital One Customers. That fine print is to prevent people from repeatedly applying for multiple Savor One accounts and taking advantage of the same bonus multiple times. From what I experienced, it seems like they can arbitrarily decide who is ineligible, which is dangerous and potentially fraudulent. I was told that there are many factors that could lead to me being ineligible, but when I asked what those factors were that made me ineligible, no one would tell me. 

As a consumer I feel I have fallen victim to a bait-and-switch maneuver. I was sent a personalized advertisement by a company and was allowed to go through the entire application process under the full impression that I would be eligible for this bonus. Otherwise, I would not have applied for the card. Capital One has relied on their own vague wording in their contract to arbitrarily deny people from the spend bonus for any 'reason ' and this seems very wrong to me and I feel taken advantage of as a consumer. 
They knowingly offered me something I was not eligible for and did not inform me at any step in the process of my 'ineligibility ' and threw multiple reasons that they felt could fit my situation.