As you know, there is always slippage between "best case" fills (displayed on C2) and real-life fills.
People sometimes send us their brokerage statements and say: "Please look at this and tell me the differences between my broker statement and C2's page and why these differences occurred."
As you might imagine, it's impossible for us to answer these kind of open-ended questions for everyone. Thus, we ask that you try to be as specific as you can when you ask questions like this. Please zero in on a few trades in your brokerage account that you are perplexed by. An example of how you might ask this is: "On June 12, I see a trade in my brokerage account at 12:34 pm Eastern Time to BUY 1 S&P at price 1234.56. But the trading system I subscribed to shows no such BUY order anytime near that point of time. Can you explain?"
When we have specific questions you'd like us to answer, we will be very happy to spend time helping you find the answers.