Colouring suggests it's a winter white dwarf hamster (but probably still a hybrid even if it looks like a winter white. Hybrids can look like either a Campbells or a Winter White but have genes from both species). Have a look at this link - scroll down the page - the colourings and markings of the winter white are very similar. So unlikely to be a Roborovski.
The White Hamster • Hamsterific!
Yes CMB it does sound like a made up name like Teddy Bear hamster but can't think why a hybrid would be speedy Gonzales lol.
Ask the breeder again what it is!