Error 15-200 while connecting air conditioner

Struggling to connect air conditioners Samsung Windfree Evo to my network, getting error 15-200
Tried a million times:

  • wifi 2.4 GHz
  • no special characters in wifi name
  • no special characters in wifi password
  • wpa2 only

I tried everything. It does not work, for any of my three air conditioners.

This said, I want my money back, even if I purchased them in 2019 (never worked).

I ask the support to provide me the procedure for the reinbursment.