Discovery Insurance Cover/ Payout refusal

We have a household content insurance with Discovery. First our washing machine broke and Discovery refussed to cover it saying it is a "wear and tear". Now, our television died due to the on/off powercuts (loadshedding) still Discovery does not want to cover. Why do we pay premiums for insurance when we experience issues then we are not assisted. To make matters worse, the assessor that Discovery sent, took our tv and left with it now Discovery says it won't cover our tv and they are not aware that the assessor took our tv. Is this not theft??? Can someone offer assistance?