Theres only one authorised Sunbeam dealer in SA, located in Park Holme. They were OK when my 6910 needed repairing, but very slow. You can get their details off the Sunbeam website, otherwise PM me.
Coffee Craft used to repair Sunbeams but unfortunately no longer do. I would much rather have used them given the choice.
I believe your problem is not uncommon. A search of the forum would probably reveal fixes for it. Otherwise Anger Management (our resident 6910 guru) will probably be along shortly to advise.