I'm assuming we should be getting that back any day now then?
There are 7.88 million households in the UK. If each of them is to cough up £68 to cover the cost of the failed firms (although why the public should be paying for these losses is beyond me as I'm guessing that the money owed by the failed energy companies is to Centrica who have a monopoly on supplies in the UK and own British Gas), then that will give a total amount to be repaid of £535m (7.88m x £68) : more info here
Centrica's profits have increased fivefold to £1.34m this year, more than double the £535m cost of the failed businesses. More info here
Although the £68 per household figure doesn't add up! Take the difference between the tariffs in my previous example and times them by 365 days and I'm paying £178.85 per year more that I was. Where is the additional £110 on top of the £68 going? I'm assuming it's not on 'green levies' as they have been cut from £172 last year to £153 this year : info here