I logged in this morning to use the treats that I collected so far in this Halloween event, and it looks like they are there but I can't use them. My basket looks like it has 1181 treats but I only have 17/2500 so I can upgrade my basket. It looks like it upgraded overnight from Horrifying to Petrifying (maybe, I don't remember, and I can't find anything in my logs).
Am I just out of luck like this is how it works, I had more than 1000 treats yesterday, it would be a shame to lose all those.