KathleenC - bad advice again from a Telstra employee.
If I do as you suggest, yes, the service will be cancelled.
However I will no doubt be informed that I am terminating the service early, and Telstra will then try to apply early termination charges as Telstra will find me in breach of contract.
Telstra now has 14 days to rectify the speed problem or be found in breach.
At that point I will phone 132200 and cancel the service.
You either do not know Telstra procedures or you have an edict to provide "advice" that are favourable to your employer.