The webpage you quoted ( [login to view URL] ) contains the following markup
<li><strong>Phone</strong>: <span><a href="" class="phone_link" lid="1350">[get phone number]</a></span></li> <li><strong>Address</strong>: 252 William St, Perth, Western Australia, 6000</li>
Note that 1350 number, and how it is used in the following link
[login to view URL]
which retrieves the text (08) 9328 2868.
So the requirement is to extract that 4 digit number from the webpage e.g with regex pattern class=\"phone_link\" lid=\"(.*?)\"
retaining the bit in brackets, and suffixing it onto url [login to view URL]
You could use WebClient but it is generally more effceint to use HttpWebRequest
Happy to provide a working method based on HTTPWebRequest which takes url as a argument and returns the webpage as a string