Re: how can a get back my deleted messages and deleted contacts on samsung galaxy y for free
Welcome to Android Central! How did you mistakenly format your phone? It's not a one-touch procedure--you have to confirm that you want to factory reset or format your phone after some prominent warning messages.
If the messages were in the stock Messaging app, then they're gone. You could try contacting your wireless provider to see if there is any way to recover messages from the server. If they were on some other 3rd party messaging service like WhatsApp, then they might have the messages in their server as well.
If the contacts were stored in the Phone Account, as opposed to your Google account, then they're gone too. This is why users should strongly consider saving their contacts to their Google account, because if you accidentally format your phone, the contacts will still be in the cloud.