No one is arguing that those records are mandated to be kept forever.
The question is whether Putin ordered them to be destroyed despite those requirements. You said you laughed when heard the news, implying that it was impossible to be true. I'm just asking how you know it's impossible. All you've given me is that it's impossible if you're following the law.
Politicians breaking or bending the law isn't exactly an unheard of concept.
I'm not trolling you, I'm genuinely curious how you're so confident in your government. If I were to come up here and say "President Trump never obstructed justice, because it's against the law to obstruct justice", you'd have a hard time taking me seriously.