Do I really need to replace my SSD?

About three months ago my 11" macbook air fell from the table and landed on it's front left corner (if it's before you as if you want to open it). There was some minor observable damage (a small dent). But the laptop worked just fine for about 3 months. And yesterday I tried to turn it on and got the "Mac OS utilities" screen. Disk utility tells about the "invalid B-tree node size" and I can't do anything about it (fsck, fsck_hfs etc. do not help). Also I can't turn it on in the safe mode. So I gave my laptop to one of the repair companies. They tell me that I need to replace SSD and that all info is 100% lost. But the SSD in macbook air is on the opposite side from the one that it fell on. And it worked fine for 3 months or even more. So, is it possible that what they tell me is true, or do they just want my money?

P.S. And also, I live in the country where there are no official Apple service centers or something like that.