I called TPG to complain and was told the issue was on my end, but my internet suddenly became fast and reliable the moment i checked after the call. It remained fine for the rest of the day, but was back to crap the next morning.
Unfortunately magic doesn't exist in the world. My home internet connection started having the same issue (extremely slow speed and continuous dropouts) since around 10:45pm last night.
Called TPG this morning requesting to proceed with my cancellation request that was put on hold last night and was asked to give it one more try. Given I am at work, I'll have to call them again once I get home this afternoon. If it's still not working properly (which I believe it would be the case), then I'll have no options left but to move onto another ISP.
Am considering abandoning my home phone line completely and go with Wireless broadband while waiting for NBN to become available in my area....