Namibian work permit when changing jobs

Good day

I would like to find out whether it is true that you need to apply for a new work permit when you change jobs in Namibia as a South African expat.  If you decide not to take the job offer that got you the visa as a better offer came up, can you use the work permit for this different job?  If not, what do you need to do to have this job permit altered for the new company?

I also want to know about what happens to your work permit if you get fired for any reason.  If you have bought a house in Namibia and moved your whole life and family there, it is a bit worrying that should your work permit no longer be valid if you lose your job you may have to leave the country within 48hrs.  What happens to your house and pets etc?  If you already have a new job lined up, is there an overlap period while you wait for the new visa during which you can stay in the country and continue working?  A new visa can take a few months... And not earning a salary while waiting for a new visa is not really an option.

Any clarification/advice on the above will be much appreciated.