I did whatever the situation dictates. If I see the call and can answer I do. If I miss it, I listen to to the voicemail. Nine times out of ten they specifically leave messages saying to call only if able. But that's my store. If they don't indicate one way or another, I call back. But I was a sucker for my store and more than wanting hours - because I almost always had too many && was being called when really desperate (because it generally was going to put me in ot: I.e I was at 36 for the week, but they NEEDED someone) -- let them know as a courtesy. I got along with my leadership & they were really good to me in return.
I'm not a fan of last minute notice myself, so I always picked up shifts where I could and got my hours set on my terms when possible. On more than one occasion I worked out swaps among multiple people - where I gave up a shift, only to be able to cover a shift when I knew no one else could && it would be problematic for the store. So, I didn't get flack if I Turned down a shift anyways.