You may have done due diligence in registering your company name and domain name, but you don't appear to have done any due diligence in registering any trademarks. A search on the Canadian Intellectual Property Office's trademark database turns up 0 results for anything relating to "twisted melon", and nothing owned by you under either your personal name, or your business name. There is also no sign of anything registered with the USPTO, or the Intellectual Property Office in the UK (where the twitter account holder is).

So, according to Canadian trademark law, you have no proof of trademark ownership, and don't even have exclusive rights to "Twisted Melon" on a national level, never-mind on an international basis.

I do see, however, that "Twisted Melon" is trademarked by someone else in the UK.