Can't backup my iPhone because "Not Enough Storage" Message (I definitely have storage)

I have an iPhone 4S, updated to the latest software (iOS 9.1). For some reason my iCloud automatic backup stopped working and I can no longer manually back up my phone either. When I try to manually back up my phone, I receive the message, "Not Enough Storage. This iPhone cannot be backed up because there is not enough iCloud storage available..." Now I know this isn't true because I just purchased the 50GB upgrade in an attempt to solve the problem. I have gone through many ways to solve this problem which seemed to have worked for other people, but they didn't work for me. Any suggestions are appreciated!

Thanks