Final Update ---- For all the ones that helped, thank you.

1. DOT acknowledged my complaint and told me I should expect a response from Delta
2. Delta acknowledged my complaint
3. Delta contacted me with resolution. Modified my ticket that rebooked me on a much better return leg that was refused as available, mileage award etc.
4. VS will need to compensate me for the leg that is still there on outbound under 261 rules. Not worried for now on getting that as it is required by law.

Problem solved and it would not have been solved had I not filed a complaint with resolution to DOT, etc Thanks everyone.