Where are the tournament rules posted? It is quite obvious that normal Swiss system rules are not implemented in chess.com Swiss events.
Pairing a 0.5 against a 2.0 in the third round WOULD NEVER HAPPEN in a normal Swiss. It frequently happens here.I've played in several live tournaments, and even won one or two. EVERY ONE has left me saying to myself, "Never again."
The rules are briefly explained here, but admittedly the page only refers to Wikipedia for the Swiss rules.