The problem was they allowed the currency to devaluate in a matter of days. People with CDs or mutual funds with long withdrawal time lost a lot of money. I'm talking about going from 18pesos = 1 usd to 36 pesos = 1 usd in something like one week.
You can actually see how the lira is losing against the usd since 2008.
Now, this should in fact raise the inflation, but it seems that they indeed chose a way to compute inflation that doesn't show this effect as much.
If the government is under reporting inflation that is a problem with the government. The obvious solution is to just report correct inflation. Once the government has reported correct inflation numbers the Turkish central bank must raise interest payments and that would mean at least 52% interest. The fundamental problem doesn't change though. People are still fleeing the influence of the Turkish government, not the currency. You need to trust the government and the government must eliminate internal corruption.
...which is exactly why they're turning to crypto.
...which is exactly why Turkey enacting currency export controls, like banning crypto.