It is something that it shouldn't have happened. I wouldn't be happy at all if that would happen to my binoculars.
But I would absolutely start by calling Swarovski for them to keep up with their after-sales reputation. (Or do it via a local official dealer.) In fact, their quite legendary after-sales service/reputation is one of the reason to consider buying Swarovski optics, new or even second hand. Many have great experience about their service (even when second hand, old models, or (from a story I once heard) in another continent than originally bought). (It's the reason why they keep high second hand value.)
And your binoculars are only a few years old.
With the DIY-work done on these binoculars in the meantime, I would understand though if Swarovski wouldn't be as "helpful for free" anymore as they usually are.
It's a bit surreal to be honest. Well, as "just a tool", it's fine replacing the leatherette yourself with some tape etc.: it won't impact the view etc. But the leatherette Habicht are not the first binoculars that I would think of of being bought purely for their functional qualities... If, on the opposite, one would worry about or consider also the 'value' of the binoculars, it is very likely that the shipping costs would have been way lower than the decrease in (second hand) value caused by the DIY-intervention.
I would still call Swarovski...
Also, regarding shipping costs, you might only have to pay for the one-way shipment to the importer/intermediate/some official dealer in your country, depending on how they further take care of the matter. (Though your binoculars might be away for quite a few weeks. But that would be little time/price to pay for the result, I think.)
).
