Possible to change single-entry to multiple-entry?

I purchased (for 192 Aus. dollars) a visitor visa in Sydney. I tried to persuade the office to grant me a multiple-entry visa, but they gave me a single. I feel fortunate that I got an extendable visa, however.

I had to give up my ARC and resident visa b/c I didn’t re-enroll at a detention camp known as Shi-Da and have been in Australia on vacation for 3 weeks. My original visitor visa from the US was multiple-entry.

Anywho, is there any way (save doing a little forgery) to convert my single to a multiple? It’d make life a bit more “free”.