Your unjustified enthusiasm for being included in a directory with such a poor design make me think that maybe you created this directory yourself and are just trying to promote it here... because I find it had to believe that Amazon, Google, Paypal payed money to be included there.

But I hope that is not the case and my answer to your question is: my small company chooses to list its contact details on the website and other places where it can be easily found by our clients, not by telemarketers like EGOL correctly pointed out.

The rel="canonical" was introduced to avoid duplicate content issues. It has nothing to do with links, internal or external.
 You use rel="canonical" to tell search engines which version of a page you prefer to be indexed.

If you prefer to tell nothing, or if there is no way a page may get indexed with a different URL then you don't need to use rel="canonical".

You are saying that your page has no external links pointing to it - but how can you control that? I may find your page, like it and link to it! This is how backlinks are supposed to work.

As you probably know each url can we written in different ways and still point to the same content. What if you prefer your page to be indexed as http://www.yourdomain.com/yourpage and I instead link to http://www.yourdomain.com/yourpage/ (note the ending /)? In these cases using rel="canonical" may help not losing any link juice.

I hope this helps.

In this video from Google Webmasters about content, https://www.youtube.com/watch?v=y8s6Y4mx9Vw around 0:57 it is advised to "archive any content that is no longer relevant".

My question is how do you exactly do that? By adding noindex to those pages, by removing all internal links to that page, by completely removing those from the website?

How do you technically archive content?

watch?v=y8s6Y4mx9Vw

In some cases Google rewrites the title of web pages in its search results pages. Here is the exact answer from a Google Employee about this issue:

In general, when we run across titles that appear to be sub-optimal, we may choose to rewrite them in the search results. This could happen when the titles are particularly short, shared across large parts of your site or appear to be mostly a collection of keywords. One thing you can do to help prevent this is to make sure that your titles and descriptions are relevant, unique and compelling, without being "stuffed" with too much boilerplate text across your site.

(source: http://productforums.google.com/forum/#!msg/webmasters/GxPvar_uSwE/ARAsgZ5Rt0kJ)

In your case I believe Google decided that your page is also relevant for the keyword "CCTV Cameras" and added that to the page title.

Are you sure it is negative SEO or is your site actually containing these keywords? 
Your website may contain that keywords if you were hacked.

Go to Google Webmaster Tools and check if there, under Optimization -> Content Keywords these strange keywords appear. If they do, check your website'c source code, someone may have injected strange text/links in your code.

As for Negative SEO use opensiteexplorer.org to find those bad links and use the Disavowal Tool to block them.

For websites that have their content not publicly available there is a solution from Google to index it, is called "First Click Free" and consists on providing to the visitors that arrived to your site via Google search the entire piece of content ranked in the search  results for free.

In Google Support they explain it better and in more detail, so you should read this: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=74536 and also the technical requirements.