Sounds like the USB-C ports are either damaged or have failed. If you are lucky, only the USB-C ports are damaged as they can be replaced, but there is a good chance with all ports not working for either data or power that the Logic Board is bad and will need to be replaced which is very expensive. If the Logic Board needs to be replaced, then you hope that the Apple Authorized Service Provider is able to recover the data by using an Apple service utility, but that utility transfers data at very slow USB 2 speeds with a max of 50 MB/s which is painfully slow and will take days even for an SSD. I'm not sure an Apple Store will do this since Apple assumes people are using Time Machine to back up their Macs. Some AASPs may take advantage of the Apple service utility to attempt data recovery for an extra fee, but others may not even bother.
Sometimes damage to one USB-C port can affect the other USB-C port on the same side. Usually when all four ports are bad, it will more than likely means the USB chip on the Logic Board is bad even though there is a chip for each port, but due to how the circuit is wired for power, one bad chip can prevent any of the USB-C ports from working (at least for charging).
Try rotating the USB-C connector on the charging cable 180 degrees upside down on the off chance only half of the USB-C port is bad....try this with each port and maybe you will get lucky and get the laptop to charge, but you may not be able to transfer any data over the USB-C port...could use a network transfer with file sharing enabled.
Users should always have frequent and regular backups of their computer and all external media (including the cloud) which contains important & unique data. There are a lot of ways to lose data these days. It is nearly impossible to recover data from these newer Macs due to how SSDs work and all the new security features. SSDs and computers can fail at any time without any warning signs.
