Which of the following statement is incorrect?

${\mathrm{XeF}}_2$ and ${\mathrm{XeF}}_4$ are non polar

${\mathrm{XeF}}_2$ and  ${\mathrm{XeF}}_4$ are planar

${\mathrm{XeF}}_6$ has perfect octahedral structure

${\mathrm{XeF}}_5^{-}$ does not exist