Data loss is always bad. Unfortunately you are in the forum about Sandisk Extreme SSD drives with SATA-interface for desktop and notebook computers and as far as I know the Canon 600D does have an SD-card slot but no SATA slots/interfaces.
Therefore I assume you are in the wrong forum.
BTW: Even if your data is lost the SD-Card may still be functional - sometimes the problem is on software level. Additionally warrenties usually do not cover lost data - only the stat storing device itself.
If the images are important make a raw copy of the SD-card and send it to a data recovering service.
