We can always say that there always exist at least one limit point of a bounded sequence (why??)[ If It's infinite then we can apply Bolzano weierstrass theorem, otherwise it must be finite and must have a limit point].
Let $(a_n)$ be a finite oscillating sequence. Suppose there exists a limit point say $\alpha$ and since $(a_n)$ is not convergent implies there exists a subsequence which doesn't converge to $\alpha$ and the subsequence thus obtained is also a bounded subsequence, again by Bolzano Weierstrass theorem we get a new limit point.
Hence $(a_n)$ has at least 2 limit points