Someone imported it, someone's selling it in the stores.
If the price of the "disposable" is, say, £5, make the deposit £50. Suddenly all the vapes will end up back at the retailer.
And make sure retailer has the financial incentive to return the used disposables and that's it.
I'm confident the lawmakers have been bribed to refuse to tackle the problem, otherwise how you can explain minimum price on plastic bags but tolerating toxic landfill fires and staggering waste of lithium (recycling will inevitably br fixed soon).
Even in the UK, they've added restrictions to it but...surprise, surprise the Turkish/Kurdish corner shops all have a steady supply, with nothing being done about it. As a foreigner living here it's honestly pathetic how disengaged the public here are with things like that. People drive like absolute wankers, too.