The short answer:
no.
The details:
Anyway you hash it, it's too expensive to setup a chat with any of these systems since their BaaS model is based on charging on a per number of calls basis.
I had to work out a lot of the logic my self using parse.com and now that I'm implementing an XMPP solution, the quantity of work is the same to get something working.
My alternative solution:
Use an open source xmpp server like ejabberd on something like AWS and then use one of the APIs to connect to it.
Contact me of you need more info on my experiences:
@andrescanella