The exchange is at 13 OBR, not 15 (corporate offices).
The co-ords (151°19'40"E, 33°38'17"S) point to no. 15, so they're wrong (although the decimal co-ords (i.e. 151.32782E, 33.6382S) just touch no. 13); better co-ords are 151°19'40.2"E 33°38'18.0"S (151.327833E, 33.638333S).
Note that according to the nameplate it's "Avalon Exchange", not "Avalon Beach Exchange".
Avalon Beach Telstra Exchange
