Autoroute peage transponders

[GG33]

I heard recently that sanef have changed the way they charge for french toll transponders - there is a new UK company (or something)
My question is: Do the old style white transponders still work? I think its called a 'Melodhy' and debits my credit card. Havn't used it for about 18 months anf just need to check prior to an upcoming trip.

Cheers

GG