Dishonest Customer Loyalty Agent

Three weeks ago I received a call from a customer loyalty agent who was calling to offer a really good promotion. I accepted but did not receive what was promised. I reached out via live chat only to be treated very poorly by the first agent (she intentionally disconnected on me when she could not answer my question) and then I had to once again reconnect and got another agent who tried his best but after 30 minutes indicated he could not help, and that I would need to call customer service because only they could fulfill what was promised. I then called the following business day only to be on hold for 20+ minutes without success. I did receive an email from someone who asked what time should they call and I provided the times  but unfortunately they never called. I just wish someone would pull the call recording from when the agent called and made promises she apparently could not keep. I am extremely at work and do not have the time to sit on hold for 20 - 30 or even 40 minutes. (That is a really embarrassing average speed to answer. I bet your service levels are in the basement.) Nevertheless, I am at a loss. I have no idea to work through this issue other than filing an FCC complaint and I'd rather not do that. Please help me. Tell me how to reach the customer loyalty team directly or at the least how to get help without having to wait nearly an hour.