Last month, I was in a store (just a department store) And I saw 3 guinea pigs in this little aquarium.... I felt sooo sorry for them

(they were full grown Abys)....and I went back to the store the next time, and there was only one of them left, and I went back to the store yet again like a month later and that same piggie was still there, I'm wondering if I should get the poor thing and take care of it or just leave it for the store to take care of.... what should I do???