I’m so sorry that happened! I know multiple people reported something similar in the fall, but most of them were able to recover at least partially. Your situation sounds really bad. 
Personally, I don’t recommend smartthings if your primary protocol is zwave for two reasons.
First, the obvious: Samsung themselves have said that their priority going forward is Zigbee and Matter over thread and WiFi. Their newest standalone hub, the smartthings station, doesn’t even have a Z wave radio. And the built-in hubs in other Samsung devices from soundbars to refrigerators Don’t have Zwave radios either.
Second, more subtle: smartthings implements its own proprietary architecture layer over the top of the independent third-party zwave standard, and they have chosen to do so in a way that actually gives you fewer zwave features then you get on other platforms. For one thing, no network map. No replace utility. No official way to set z wave direct associations. But there are other gaps as well. I have documented the ones I know about in the following thread:
Gaps in SmartThings’ Zwave Implementation (2022)
As far as what else to choose, there are a number of options, including the Zooz Zbox, Hubitat, Homeseer, etc.
The Zbox is “zwave centric” and tries to be more consumerfriendly, although it’s still pretty techie.
Hubitat is also keeping up with new Z wave standards, and is the most like the old smartthings, so might be the easiest transition in that sense. But it’s definitely for power users. It supports pretty much the same set of protocols that smartthings does plus a couple of extras, including a Homekit integration. So, if you do happen to have any Zigbee devices, you could definitely use those over there as well. However, there matter implementation has lagged behind SmartThings, as @h0ckeysk8er Notes below.
There are other options too, of course. Different ones will work for different people.
Hubitat has a very active user community and actually quite a few people use both smartthings and hubitat, so that’s yet another option. There are a couple of community built integrations, which let you combine the two if that’s of any interest.
Zbox is based on fibaro architecture, but with UI improvements from the experience of Zooz. Slicker marketing, maybe. Solid engineering underneath. This one is really intended only for zwave.
So you certainly have options to consider.