Unable to add any DPs in a package

Hi All ,

I have created the package and it is available on the SCCM console.

1) First time i was able to add the DP into the package.

2)Now we have deleted those DPs from the package.

3) Again we are trying to re-add those same DPs but it are not showing in the package distribution points.

4) But we can able to add other DPs.

5) We have refreshed the package and checked but still we are unable to see the old DPs

6) Moreover the package version is not incrementing after add a file to the source location (Update Distribution Points).

Help me to resolve the issue.