But i dont have warrenty to give pressure on them.

Please help me here
https://www.nairaland.com/phones

Finally i am here to get some solution.
The day before yesterday i updated my C7 from ANNA to BELLE in my nearest NOKIA CARE.But after update i have noticed that my C7 inbuilt mass memory has corrupted and i even can't format it manually from device too,it say 'ERROR OCCURED,OPERATION CANCELLED'.When i try to hard or soft format with *#7370#,the format was not occured and just NOKIA in screen for about 1hr and phone did not start up and finaly again i went to nokia care and they again installed the BELLE but MASS MEMORY did not appear.Nokia care told me that my mass memory get corrupt so no way to recover it.So i have to use the external SD card.Also now i can't remove installed app and it say REMOVAL FAILED.So,plz help me can i able to recover the 8GB free MASS MEMORY by any way?