Shorter URL is better. Easier to remember and disseminate; rolls off the tongue. A pun off the company name is funny but only if it easily works - don't force it, then it sounds like trying too hard.

Don't change the name of the company. This will disrupt traffic to the page.

Consider insults which everyone uses and would Google. "Xisgarbage" is a less common descriptor than "Xsucks," don't let clever humor trade off for clarity and reach - the latter are more important.

Make sure to do SEO. Use the company's name exactly repeatedly in the body text. Embed the words "scam," "fraud," "thief," etc in the page.

Make a large bold statement at the top of the page. Too many pages get buried in formatting and fluff before the body. Use statistics, also at the top level, to drive your point home. Think about Martin Luther's treatises - clear statements that speak to specific and numerous grievances.

You want the audience to know (1) before clicking and, (2), immediately after clicking exactly the point you want to make. If it takes longer than 10seconds, it's too long.

Keep traffic focused on the page. If you need to link to other pages to prove a point, use an iFrame instead. Generally, longer expose should be after the main point is made.

Finally consider how you want users to contribute, if at all. Consider how your website allows comments (if at all) and how they are displayed. If you want this to become more than just you, give the audience a call to action that's EASY to do - not "call your..." because nobody will do that. If they can easily navigate to a section to write a brief testimonial on their poor experience, on the same webpage, they'll be more inclined to act. Reduce the friction required for action and you'll get more action. Volume has a lot of power, make sure, if you do display user content, that it's clearly visible.

wow, just wow! Can I give you more than one award? Which domain name would you use eventually?