There's no one from Valve on the VAC forum, and even if you contact support directly, they'll give you the same link I gave you, as it contains everything you need to know:
https://psteamhelp.yuanyoumao.com/en/faqs/view/4E54-0B96-D0A4-1557

And if I didn't violate any of this, then maybe the VAC blocking was just for nothing.

As you can see in the link at the beginning, it's a GAME ban, and these are just examples of possible reasons; there are more.

A game ban that's been issued once stays in place.

引用自 Langa?：

Why did I get banned? I didn't do anything wrong and I didn't play with a cheat. I swear, can you call me for an investigation? I don't understand.

Cheating isn't the only way to earn a game ban.

引用自 Langa?：

Why did I get banned? I didn't do anything wrong and I didn't play with a cheat. I swear, can you call me for an investigation? I don't understand.

引用自 Langa?：

And if I didn't violate any of this, then maybe the VAC blocking was just for nothing.

1 game ban on record | Info
0 day(s) since last ban

see link in post 1. your account was caught doing something against the rules and its permanent

and what to do in such cases

引用自 JacquesPatat：

引用自 Langa?：

Why did I get banned? I didn't do anything wrong and I didn't play with a cheat. I swear, can you call me for an investigation? I don't understand.

引用自 Langa?：

And if I didn't violate any of this, then maybe the VAC blocking was just for nothing.

1 game ban on record | Info
0 day(s) since last ban

see link in post 1. your account was caught doing something against the rules and its permanent

引用自 Langa?：

and what to do in such cases

引用自 JacquesPatat：

1 game ban on record | Info
0 day(s) since last ban

see link in post 1. your account was caught doing something against the rules and its permanent

First, try a little reading comprehension. It does wonders for your understanding.

引用自 Langa?：

and what to do in such cases

Well you can start by reading what is posted regarding your ban

引用自 Langa?：

and what to do in such cases

You know, if I give you a link with everything in it, then you should read it, which is bad enough that you didn't, but then asking again what you should do after someone else tells you to use the link and read the content, sorry, but I really don't know what to make of that kind of behavior.

If you're expecting someone here to magically remove your ban and you can ignore everything else, then I have to disappoint you; that's not how it works.