Study Argentine history. They have tried everything imaginable, and managed to control inflation for a while. Look at the 1-1 peg between the peso and the dollar that lasted 9 years. It's much more complicated than you think.
Every country that did that got inflation under control, the problem is Argentina doesn't want to spend less, so they print like there is no tomorrow.
Currency pegs are one of those things that known to fail every time, by the way.
Anyway, the answer to the GP is that the government will need to severely cut their spending. That's the same reason on every country with high inflation.