Replaced iphone wont back up to icloud

Help!!! I had my iphone 5 replaced yesterday (as the power button had stopped responding) restored from icloud successfully and now i cant back up to icloud as it says i dont have enough space. The new phone is the exact same size data as my old phone iv not taken anymore photos or downloaded any app which would of increased data size so im puzzled to why my new phone wont back up..... 😕

I have been into the storage and tried turning off any apps that didnt need to be backed up but this hasnt helped but these were all backing up on my previous phone