Problem in writing data on W49f002U-12B flash memory

Hi guys,
i am trying to interface the flash memory W49F002U-12B using arduino mega 2560 :
1- There's no problem in reading data from the memory (easy operation as other EEPROMS). But
2- The problem was in writing data (actually there's a command sequence you must do before writing data on the memory (as indicated by the datasheet) and i've already done it !!!! but when displaying the contents of the memory ----> nothing is changed (memory contents are the same as before doing the previous stuff).

the command sequence is in the attachments also the code that i have programmed for writing data.
so, any suggestions of what i should do ???

Screenshot 2020-11-27 214748.png

Screenshot 2020-11-27 214748.png