Hi Alleycat, I believe your Strata Manager should know from the OCs records who the supplier rather than the retailer is an may have a contact number / email.
Alternatively, your retailer should be able to tell you and your local council will also be able to do this as well… I had to contact them for a similar purpose and they gave me the correct contact details!
If your having trouble with them, Fair Trading will definitely help but they usually fix this kind of stuff quickly through independent contractors!
I hope this issue gets fixed quickly for you, and your SM provides you assistance to get it done all the quicker. Your feedback should also be well received by your OC in case other owners need to do the same, which I am sure they will have to at some stage.