Verbal agreements will only get you so far. Most agreements have a term, and if they don’t, then maybe interpreted to be subject to termination by either party at any time. Or if you can make a credible case that there was some understood term based on the facts and circumstances, but it generally can’t be perpetual if not so stated in writing.
You’ll be wading into the waters of equitable remedies on this one. For example, if you can show that you reasonably relied on certain representations or courses of conduct and have spent money on the understanding that the business would continue. But again, for some term, not typically forever. In this case, maybe to get you through the next season, or if you’ve say, hired employees and given them term and will owe them money if these guys cut things off abruptly, then for some reasonable term corresponding to the duration of their engagement.
But if there’s nothing in writing, you face an uphill battle, and the weight of rapidly piling legal bills saddled to you won’t make that uphill journey an enjoyable one. And if in Canada, and you lose, you may find yourself liable for their legal bills too.
That said, the very threat of litigation in the context of working out some reasonable compromise could be effective. At least to get them responsive again and see how shaken they may or may not be.