When i purchased my iPhone 6S plus last September my iCloud storage was upgraded from 5g to 50g. Then several months back it went to 5g. Why do I no longer have the 50g? Nothing was indicated that it would only last a few months.

As far as I know there never was a free 50 GB. My better half bought an iPhone 6s in September too, and did not get one. There was however a reshuffle of the iCloud storage plans in that month. People who had 20GB were upgraded to 50GB. This storage is not free however: it's 99 cents per month.

Are you being charged for the additional storage? If so, try contacting iCloud support.

Contact link bottom left.

iCloud