I know that quitting without notice is a really shitty thing to do to your co-workers and I feel terrible, but I've been at a store in the UK for a few weeks (less than 3 months) and tl;dr it's been really rough. My manager hasn't been accommodating at all so I've been made to work ~60 hour weeks including weekends, and some of my co-workers are nasty also.

Yesterday I snapped and couldn't bring myself to go in, so called in sick, and in the evening sent my manager a message to say I was quitting. Today (Monday) I haven't gone in either.

Of course I won't use this job for a reference or anything, and hopefully won't have to set foot in a Starbucks ever again, but what are the possible legal repercussions, as I haven't given the 1 week notice I'm supposed to? I'm happy to pay them back everything I've earned, but I can't afford to pay more damages if they sue or whatever (though idk if they'd go to those lengths over this).

Thanks in advance guys.