IOS 9.1 problem - cannot connect to wi-fi
My son has a iPhone 5c which had to be replaced last week due to a hard ware issue. The new phone had IOS9 but it will not connect to the wi-fi when the old phone was fine. It will not send text messages as iMessages either only text messages. We have tried rebooting the phone, forgetting the network and other things but nothing works. Apple support have blamed the router but everyone else in my sons flat at University is able to get wi-fi on their iPhones. It must be IOS 9 as the problem but Apple refuse to accept it is their problem. Can anyone help with this and have any ideas of how to fix this? Thank you for any help anyone can suggest.
iPhone 5c, iOS 9.1