I wrote 'sorry' also, but thinking about what I would say in a shop - 'Excuse me...' would be the preferred words. Tricky this translation business.
"Excuse me" is asking for permission. "Sorry" is asking for forgiveness. You say "excuse me" before doing something that might inconvenience someone. You say "sorry" after having inconvenienced someone.
Yes, but you say neither before interupting someone. You say "excuse me".