So I recently got my garage epoxied and after about a week it started pealing off and I was wondering if I can sue the contractor as they aren't answering my calls or replying to my messages. 

The reason I'm not fully sure about suing is that the contractors seemed young maybe even under 18. Also, there was no written contract for the job and the only information I have of them is their phone numbers. 

So, is this something worth suing for or would it be a waste of time.

(Ontario, Canada)