Um, I think the problem here is that DL1619 ATL-SAV on Oct 6 actually operated on time (according to Flightaware). It was canceled on 10/7 and 10/8. When OP talks about cancellation, I believe he means that the agent affirmed he was cancelling his trip (due to the hotel closing), not that the flight itself was cancelled.
So this does not appear to be a trip-in-vain situation (since the flight operated on-time). OP was likely entitled to a free change due to a weather waiver, but not a full refund. There was likely confusion when he called to cancel, with the agent probably assuming he would rebook at another time (under the weather waiver rules), while OP assumed he would be getting a refund.
This makes sense.
Rereading the OP and the statement that this is a long-time frequent flyer, it does appear that OP was able to cancel the second segment (ATL-SAV) as part of a "weather waiver" not because DL cancelled the flight.
I presume that the terms of the waiver permit OP to rebook or have a credit against future travel, but not a refund to the original form of payment.
If DL actually cancelled the ATL-SAV segment before OP asked that it be done, then it is not that it is a "trip in vain" it is simply that DL is unable to perform the contract, e.g. fly OP from YYZ - SAV with a connection (note that this is a connection not a stopover and that is critical) and thus OP may have a refund.
It would be helpful if OP would repeat exactly who did what here. That may be part of the problem with DL.