After One Year, Still No Word From SAPS

HelloPeter. Last year January my brother was ******ed/stabbed in Daveyton. It is with great sadness, to say that till this day we have not heard anything from the detective, unless if we go to the station and ask what is happening! And the response will and still is, that when we see the suspects we should phone the detective! Another response was that one of the suspects is not feeling well, so he can not be taken in for questioning! We can not let this issue be swept under carpet as a family! What should be the next step on this matter? Your advice/service on this issue will be highly appreciated.

Thank you.