How To Get Back Deleted WeChat Messages On iPhone?

My best friend just deleted all wechat messages on her iPhone, and she was anxious to get back those deleted wechat messages. So is there any way? I cannot make sure whether she has an iTunes or iCloud backup for them. Any suggestions are welcomed. Thanks. iPhone 6, iOS 9 It is quite easy to delete some important data like wechat messages from iPhone without perception. Usually, data like wechat messages means a lot to us. Those mistakenly deleted wechat messages may be related to our bus...