Price freezes are pretty common features of hyperinflation scenarios. They aren't necessarily bad in the short term -- as you observed, they can buy breathing room for a while. But if you don't fix the root of the problem in that time, the mismatch of supply and demand works itself out in other ways.

The root of the problem varies from scenario to scenario. In the case of Brazil, it was the same oil shock that hit the US so bad in the 1970s. Both countries tried to spend their way out of it, but Brazil couldn't keep up, and its military dictatorship got more and more paranoid. The resulting civil war made it impossible to put the economy on a stable footing until a real government came back in the 80s.