Our flight ressie from ATL to DTW TK**GA was over sold. We volunteered our seats but wa...

Our flight ressie from ATL to DTW TK**GA was over sold. We volunteered our seats but was promised a new flight on Frontier at * to Detroit. They were not able to get us on that. So the mgr purchased tickets for us on Delta. We flew Delta from ATL to GRR. Before we boarded Delta. I asked the attendant if our bags would be on board. She “looked “ them up on her computer & said . We have your bags. If you don’t fly your bags don’t fly. Arrived at GRr. They do not have our bags . Checked with the baggage people. Delta said our bags were never loaded.