Lens probably does not extend or retract because of debris or a misaligned gear box. The
lens can in about 50% of the cases be repaired without having to replace it. Try to
return to manufacturer first. If you're out of warranty, there are
third party place that fix them such as camera lens repairs
. If you want to do it yourself, there are also free camera repair guide
websites that show you how to replace the lens, the replacement part is usually available on ebay.