If I mean "you" as one single person, like "hey you, call me back" then "Ruf mich zurück" or "Rufen Sie mich zurück"(the formal verson) is correct.
If I want a group of people or a company in general to call me back it would be "Ruft mich zurück" or "Rufen sie mich zurück" as formal version, notice the "s" typed as small letter. But none of these variations looks or sounds good in german.
Maybe just "Rückrufwunsch"?
"Wir rufen Sie zurück", answered by Ingmar is a good idea. Sounds good and trustfully. Or even "Wir rufen Sie gerne zurück" if you want to say hat you really pleased to call s.o. back.
I wouldn't stick with "call me back" as single English sentence on a German site.