Latest advice re: re submitting deposit

Tenancy Deposits

I recall receiving a notification some months ago wrt a case where a Landlord had been ordered to pay 3 times the deposit to a tenant as when their tenancy rolled over from a fixed period to a periodic AST they failed to re submit the deposit. It was a case called super-something and seemed quite ridiculous and against all common sense. How are Landlords to persuade a tenant to agree that an existing deposit be paid back in full to a landlord in order that the landlord have the ability to re submit it anew when the tenancy changes or an existing tenant wants a new contract period? I was wondering if this has been overturned or whether we are all just waiting to be taken to the cleaners still or if anyone has found a way to overcome this insanity? If common sense prevailed, a deposit once secured with DPS is just that - secured. What is the latest advice concerning this and how can we protect ourselves? Any advice on this matter is gratefully received.