Actually they do this after 3 months.
I once had the same issue actually. I logged in after a long time and saw that my account was all 0s even though I knew there must at least have been a tiny bit left.
So I messaged support, they explained it to me and put my account back in active and the funds were back where they were. So it was no biggie to get it fixed.

With an unused account of 1 year it's a different story and this rule (deducting 5% monthly) is not cool.