Nespresso thinks exchanging sealed boxes of sealed, unused coffee pods, is a health and safety risk

I recently bought 30 boxes of Nespresso pods to take advantage of the free Vertuo POP machine. We have a barista type Nespresso machine already but there seem to be more flavours in the Vertuo range. Let me also add that this is the fifth Nespresso that we have owned. I had one at work at one point, we had a small Inissia for travelling and we gave another one away to a family member.

Unfortunately, I didn't do my research properly and ended up buying mostly espresso strength pods. The Vertuo pods work very differently to the original machines and I now have 20 boxes of extremely strong coffee.

So I sent an email to Nespresso to ask if I could EXCHANGE, not get refunded, and pay in the difference for the 230ml pods.

I almost immediately get an email back from Tanya Ramnath | Nespresso Coffee Specialist that it is a health and safety risk to exchange sealed boxes of coffee pods. She also proceeds to copy and paste Nespresso's return policy which is irrelevant as I am not returning anything.

Can someone please explain to me why wanting to exchange sealed, new boxes of sealed, unused coffee pods is a health and safety risk?