This country is thoroughly dysfunctional, governed by ex-communists for 10 out of 12 most recent years, with neo-nazis entering the parliament 2 years ago, etc. etc. You can't expect ticket sales, out of all things, to work as expected in a country like that, can you? There have been news reports today about server collapses, hacking attacks, large-scale resellers, etc. etc.
(For the record, the previous world championships in Slovakia were held in 2011, which was one of the two exceptional years when Slovakia was not governed by ex-communists. Not that it necessarily means anything – just a fun fact... Although there's also a funny and entirely fact-based graphic somewhere showing that whenever ex-communists were in power in Slovakia, Slovakia bombed at the world championships the following year. Whereas when pro-Western prime ministers were in office, those were the best days of Slovak hockey, with lots of medals including gold. That trend goes back to the 1990s, and it's quite an amazing "coincidence", isn't it?)