I restored my iphone from the wrong back up!!!

So last night i was forced to restore my iphone , it crashed and ended up losing all my pictures and texts messages. i was using it without music, so i wanted to restore it with a backup on my laptop. But my itunes was used by someone else but before that it said it cant until i turn off Find my iphone. so after restore it ask me for a password for someone else icloud!!!!

i had this phone for YEARS!!!!

i think i still even have the box and maybe the receipt?

What should i do!!

can i show my laptop with the backup under the wrong icloud to the apple store? should i bring my box? im not sure if i still have the recept inside the box.

Can apple verify the original icloud account it was activated with in the beggining? PLEASE HELP !!!!

iphone 6 plus 128gb