Name and shame. EK have said themselves that they're broken and have basically issued a recall. If the etailer is refusing to take it then they are absolute *****. I wouldn't trust them with anything if they are trying to get away from this blatent issue.
You can RMA it directly to them with free postage though. Check their website. Iirc, you get the option of replacement with a nickel EN block, copper block or refund.
It is a hassle, especially if some retailors tell you to go through EKWB. There is a particually well known competetor of OCUK here in the UK who will take the block off you, refund/replace straight away with their own stock and handle EKs RMA themselves.
Not all EK's blocks are affected. There is a fair amount which are. The new EN nickel blocks should be completely fine.