I am thinking of using small claims ontario. My son attended an affordable private school for almost 3 years since he was 2 years old. We have had no problems with the school until 2 years later. We have signed a registration agreement initially. We expressed our dissatisfaction with the changes in curriculum after we have made our full tuition payment for the year. Promises were made but not kept. Changes were implemented without us knowing. We were frustrated and expressed our concerns. 1 week into the 2nd semester, a letter was inserted into my 5 year old son's napsack saying that we have 1 week to withdraw our son because we are dissatisfied. There were no formal meetings regarding our issues or to solve the problem. Many parents feel the same way but the owner has tried to please them. Note. My son is also diagnosed with autism spectrum disorder which they were aware of.

Do we have a chance to sue in small claims for money lost due the lack of notice. I have had to take time off from work? And other costs such as returning our registration fee, the difference in tuition costs from old school to new school? And other non quantitative amounts such as stress, etc...

It's a contract matter so, no, you cannot collect for stress, pain and suffering. I doubt you can collect for your time off work.

If you lost money and can PROVE you lost money through their negligence in notifying you, yes, take them to Small Claims Court.

You expressed your disatisfaction; their solution was to withdraw your son. Is that correct? I don't believe that they were required to have formal meetings with you.

What would you have preferred as a solution? Did you want him to stay in the school?

If they lost tuition because your son withdrew I would expect a countersuit.

It's all going to boil down to the contract - whether both of you were in accordance with the terms and conditions.

I agree it all boils down to the contract. I suspect, if you read the contract carefully, you will find that are not required to notify you or any of the things you wish they did. So the likelihood of a successful suit is small.