where can i buy my milk so that the farmer gets paid fairly.?

I am aware that farmers are generally making a loss for each litre of milk sold in the uk.
the fault lies with the supermarkets selling milk so cheap.
I would like to pay more for my milk i order to ensure that our farmers are not going out of business.
but i don’t want to pay more for milk and have my money lining the pockets of business men.
I want to support the dairy industry so where can i buy my milk in order to do that?
please note, I have no car so I am limited to shops that will be in most large towns.