From experience restoring access to a Steam account

Surely many of those present here use Steam, so I think my story will be right here - if not instructive, then at least interesting. Or vice versa.

I happened to lose access to my account. Active users of this thing will understand the whole horror of the situation, and so, I will explain to inactive non-users: the Steam account contains not only games, but also:
- Inventory with coupons, game items, collection cards, emoticons and other;
- Badges that can be collected from collection cards, received for contributions to community development or for length of service;
- Achievements in games that are not always easy to get;
- Access to friends and created communities;
- A library of personal screenshots, illustrations, videos, guides and reviews.
And some invest more than one thousand money in games. My situation was not as severe as it could be - I lost access to the slave account (the second one, that is, the additional one) - but still it’s very annoying! How to get lost? I did not receive a Steam Guard message when I tried to log in from a new device. The login password is correct, the mail is the same - but there is no message. “There is a support service!” I thought, and rushed there.
A couple of days later, a response came with a request to confirm the ownership of the account ("Proof of account ownership"). Login password is not enough for them. To do this, you need to provide any of these data:
- about a credit card;
- on payments by electronic money (AliPay, BoaCompraGold, Giropay, iDEAL, PayPal, PaySafeCard, Russian Kiosk, Sofortüberweisung, WebMoney, Yandex);
- About the Steam Wallet money certificate;
- about the license keys of the purchased games.
I sent the details of my credit card, waited two days - they say that the credit card is not attached to the account, and even if it made any payments on Steam, it does not count. They require another proof. I had no other payment information (QIWI payment data will not work for them), so I sent a CD-key (even two) and again began to wait ...
Today, after 11 DAYS, the long-awaited answer came:

They closed my ticket until I sent them another confirmation of ownership. This time they asked for something completely idiotic: write with a pen near the license key (yes, right on the booklet from the box with the disk) the number of my ticket as an example and send them a photo.
And you could go for this vandalism to get your account back - but I don’t have any boxes, all the games were bought on the network, and their license keys look something like this:

They forbid using graphic editors, they also forbid printing. What to do? Nothing. I sent them this very screenshot (only without bluer, of course), but without any hope. You can say goodbye to your account, now for sure.
So, in order to protect yourself from accidents, be sure to check:
- Is there a credit card attached to your Steam account (there, when paying, you need to check the box “use these payment data blah blah blah”);
- Do you have access to the email address for which the account is registered;
- Do you have at hand information on all payments made on Steam (not the receipts that Steam themselves send, but documents from the payment services);
- Do you have at hand license keys for all purchased games.
Only in this way can you be at least a little sure that access to your account can be restored on occasion. Because, as it turned out, Steam tech support is still an ambush, and their famous anti-human security measures (which is just a ban on using the Marketplace in a million different stupid cases) are really aimed at preventing a person from enjoying life.
Good luck to all! Do not repeat other people's mistakes, be original, make new ones.