iOS 8.1.3 screwed up my 5S
Sonce downloading the newest iOS onto my 5S it has gone from being the most invaluable tool in my self-employed business to the worst device I've ever owned. Prior to the "upgrade" my 5S was reliable, durable and able to run multiple apps at the same time. Since the download it crashes frequestly when trying to open something and innocuous as the Calendar app. It fails to keep inputed appointment dates, it crashed when opening apps, the phone freezed for periods of time that requir the phone to be hard-rebooted. The mobile data connection has worsened and so has the range of the wifi. Email addresses that are linked to the mail app on the iPhone continually refresh and read the hundreds of old emails as new, eating up data and phone memory. Regarding memory, I'm unable to take photos or videos with my phone because apparently I have asolute let ZERO space left which is an impossibility considering the limited amount of items I have stored on the phone. Even as I type this the autocorrect is doing bizzar things.
This is not the first time I've sad issues with an iPhone follwong an iOS "upgrade". The same happened with my 4 and my 4S after that. I I expected that Apple would have resolved these "upgrade" issues that deteriorate the performance of their products.
Please advise how I can return my phone to the reliable business tool it once was and not the reason I turn to Samsung.
Thank you.