Let's see if this summarize your case correctly: you feel like you're being cheated because your daily bonus is lower than your expectation. You're sure you've wagered a lot, which means you should be compensated with significantly bigger daily bonus. You asked the customer service and they've explained to you that there are multiple factor that are counted towards daily bonus, there is no single exact formula, as it depends on your loss, the house edge of the game you play, and other factors.

You insist that their calculation must be wrong, meanwhile, they insist that there is nothing wrong. And things goes in circle around this topic.