If a shop(online or offline) uses kufr acts to promote their shop, does it affect the permissiblity of shopping there?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

Buying from that shop has nothing to do with the way they promote it, even if they use ways that include Kufr (disbelief). Although it is not forbidden to buy from them, yet it is better to avoid them and deal with others instead.

Allah Knows best.