As a private organization, the DNC doesn't really have to follow a lot of the laws that we think of when we think of fair and honest elections. The organization pretty much gets to write its own rules, and ignore them whenever it is convenient. It's no surprise that big money is running politics at this point, and the DNC is where big money and politics converge.
The DNC may have been caught essentially selling access to candidates and/or the President, but I'd guess it happens all the time with both parties. Big money donors obviously get preferential treatment, better seats, more access and better dinner placement. That certainly doesn't make it right, but you can't tell me it only happens with one party.
To some degree the DNC controls donor access. There are limits to what donors can and cannot do and who can donate what. The DNC is partially in charge of this which makes sense considering who they are and what their mission is. Control of donor access helps keep thier mission intact.
The Democratic National Convention, or DNC, is embroiled in one turmoil after another. One of these new scandals is the accusation that the DNC is involved in what and how many donors can bankroll the event. This accusation is ridiculous. No donor is under pressure to put money in the event.