Why doesn't Bitcoin have live support?
Because Bitcoin is not a company or any organization. It is not controlled by anyone, it is controlled by you and thousands of people like you. Bitcoin is essentially just a definition and the people who run software that implements the definition. The person who wrote the original definition is no longer involved.
There are subsidiary companies (some say parasitic or predatory companies) that offer Bitcoin services. For example, Have your wallet ready for you or arrange for currency exchange. But these companies don't control Bitcoin. These companies are not necessarily a necessary part of Bitcoin.
There are mining consortia that have a significant impact on the integrity and functioning of the Bitcoin blockchain. However, they have no direct relationship with these people or companies, they do not work for you or are individually dependent on you and do not have to communicate with you as a person, they could not gain anything if they help you.
In short – Bitcoin is a peer-to-peer system. There is no bitcoin.
You might as well wonder why the English language doesn't have live support. Who would direct it? Why should you do it? Why do you trust them
If your wallet software was purchased, the company you bought the wallet from may offer live support. Most wallet software is given away for free. There is only "community support" and the ability to report bugs to a system used by developers (who are often just volunteers).
Who has access to a remote upgrade of my wallets?
Since the wallets are only software that runs on your computer, anyone who has access to your computer can update the software on them. You may need to request your computer account credentials or administrator access. However, this is easy if they have physical access to the computer.
If the computer is connected to a network and has remote control software installed on it, these actions can be performed remotely. If the computer's operating system or installed applications have unpatched vulnerabilities, they can often be exploited remotely to take control of the software.
In short, never keep significant amounts of money in a wallet in a computer that is connected to a network. Never give anyone else access to the computer on which your wallet is located. Never give out your private keys, credentials or other confidential information.
and then deny me access to the content
You mention the wallets "have been recently restored". Your choice of words indicates that you may have had help or someone else did it for you.
Such a person would have been able to "restore" the wallets in a way that prevents you from spending the contents. For example, by setting up "watch-only" addresses and copying the private keys or keeping them to yourself.
If I had 50 Bitcoin ($ 320,644 at today's exchange rate), I would not trust anyone to help me with it. In particular, I wouldn't trust anyone I haven't known personally for at least five years. That's a decent annual wage – I would be willing to spend work full time for one year to find out how to restore it myself, and if it works, I would consider the efforts of those years well spent.