They must be recycling enough of it to recover their £30. They may dump the unrecyclable parts into the ocean, but nobody doubts there are unrecyclable things mixed in with it. It can't be 100% recycled.
The government might as well be part of such fraud too? What do they care, if the plastics is not actually recycled.
But if they cay say to the voters, "Now we're recycling all plastics", then, some more votes, they'll get, in the next elections? (Maybe just a few more votes, if most voters also don't care)