Burger King, I believe, are in a JV with Alexander Kolobov and own 15% of the business in Russia. So they are in the process of divesting themselves of the 15% but will probably still make profit on that 15% for now and that is what they are pledging to Ukrainian charities.
M&S probably do not have financial investment in FIBA but FIBA probably pay them a franchising fee to use the name and M&S Products. (Products they are no longer getting, of course.) I would guess that the franchise agreement covers several years and the money that M&S have pledged to international charities operating in Ukraine will negate any income from future franchise fees, if there are any. If you want them to donate money to Ukraine in particular, write to them and suggest it.
The MP last night also mentioned how British Tobacco are still operating in Russia, but there is no such company. British American Tobacco announced a week ago that they are withdrawing from Russia.
You do what you want to do, I'll do what I want to do.