No such thing as getting it twice. No documented cases worldwide. There were a few (4) early on, but it's likely they had something else the first time. Acquired immunity is the best, and from what I've heard from actual experts, it's a "one-and-done", i.e. you will only get it once, and no longer be able to catch or spread it. There may be a very few outliers that didn't develop immunity normally, like those who get chicken pox more than once.
I suspect that a lot of these second and third (!) infections are either due to the shots themselves, the shots wiping out acquired immunity, or a different virus altogether (flu, colds, etc.).
Best explanation of all this comes from Dr. Peter McCullough on Joe Rogan's podcast Episode 1747. That's my recommendation for those who aren't biology geeks. He lays out all the information in a fairly concise, understandable format. If Rogan understands it, anyone can!