When you say "it was", do you mean that the company initiated the contact with your friend? When companies cold call to solicit customers there are strict consumer laws that apply.
For example, there is a statutory 10 business day cooling off period. Has it been more than 10 business days since your friend made the agreement with the internet company?
Also, your friend must have been/ be sent (via post or electronically) a copy of the contract within 5 business days of agreeing over the phone.
The consumer's rights must be explained by the salesperson at the time the contract is made and no consumer rights can be waived by the agreement.
Get your friend to have a read of this document from page 10-17 ("Unsolicited Consumer Agreements"):
http://www.consumerlaw.gov.au/content/the_acl/downloads/sales_practices_guide_dec_2011.pdf
Then get them to call the Office of Fair Trading in NSW if the company has breached their obligation/s and your friend is still having difficulties getting out of the agreement.
Contact us - NSW Fair Trading