Y'know, Impatiens Downy Mildew is a nationwide problem and cannot be
blamed upon a single supplier. It affects all bedding Impatiens (I.
walleriana hybrids and varieties) and is a strongly residual disease
that can and will appear spontaneously amongst any planting. Cool,
humid nights and rainy weather enable it to spread quickly on the wind
and an infected plant or plants some distance away can be the source
of a infection in any one garden, It is unreasonable and unfair to
imply that T&M (or any other supplier for that matter) sold infected
plants, because it is equally possible those plants became infected
after planting. I'm not a huge admirer of T&M, but I do think they
are being exceptionally and even unnecessarily fair in offering a
refund. Take the money and be grateful, but be aware that such offers
may not be forthcoming in future.