Does your Scoby really have real mould? Note: Mould only develops on the surface of the scoby. White hairs develop similar to those on fruit. There is very little you can do about mould. Buying a new culture is the best thing you can do.
Mould propagates via spores and these can be present in all the liquid and in the scoby. Since some moulds can produce strong toxins, it is very important that you really dump everything away and do not try to save the batch.