Solved! faulty USB saga

[cookiealexd123]

Would someone be so kind as to help me? I thought it would be a great idea to download Murder, She Wrote. Laptop didn't have enough GB free So I thought it would be good to use a USB. Sadly I ran into trouble trying to skip ahead in an episode and noticed my 'season 2' folder was all now gibberish. I removed the usb and re-entered it, only for the D: drive to say 'please insert disk'. I tried all the recommended tips, the only thing I found to help was getting the details from ChipGenius and running ALCOR_MP_v16.02.19.
This got the Usb working again! However, my previously 50 something gb (assuming its 64gb with some used up data) is not only blank, but also gone right down to 15 - 16gb capacity.

If anyone could explain what happened, how to avoid it, how I might get back my season 1 and 2 files of murder she wrote ,and how to get it back to full capacity, I would be very appreciative!
note
am now using diskternals uneraser and the USB has now gone to technically showing up in D: and disk1 if i do chkdsk but still says insertdisk/ inaccessible and 0mb. What on earth is going on? should i run the ALCOR_MP_v16.02.19 again?

Here is the copied chipgenius details! :
Device Vendor: Alcor Micro
Device Name: Mass Storage Device
Device Revision: 0001

Manufacturer: Generic
Product Model: USB Flash Disk
Product Revision: 7.76

Controller Vendor: Alcor Micro
Controller Part-Number: AU6989SN-GT [EC05] - F/W 940D
Flash ID code: 2C84643CA500 - Micron MT29F128G08CBEBB - 1CE/Single Channel [MLC-16K] -> Total Capacity = 16GB

Tools on web: http://dl.mydigit.net/special/up/alcor.html


Possible Flash Part-Number
----------------------------
[1CE]MT29F128G08CBCAB x 1 pcs/Channel x 1 Channel
[1CE]MT29F128G08CBEBB x 1 pcs/Channel x 1 Channel


Flash ID mapping table
----------------------------
[Channel 0] [Channel 1]
2C84643CA500 --------
-------- --------
-------- --------
-------- --------
-------- --------
-------- --------
-------- --------
-------- --------

 

[rgd1101]

new usb or used?
sound like a fake usb storage

 

[cookiealexd123]

new usb or used?
sound like a fake usb storage

I have had it for a few years and used it for school documents prior. I originally got it from my grandparents so have no idea of its origins. Not branded. looks like this:

 

[rgd1101]

was it really cheap. first time using it for more then 16 gb data? sure look like a fake size usb

 

[cookiealexd123]

I think the amount of data I transferred was between 12-18gb so perhaps. But the files all seemed to be on there ok. It was just trying to skip through videos that did it I have just plugged it in and now it is showing as being accessible again. No idea what is going on with it. all the data recovery tools i am trying don't find any history of anything being on it etc

 

[USAFRet]

I agree.
Cheap and it simply failed
or
Fake

What size was this supposed to be? 128GB?
A "few years ago", 128GB flash drives were pretty expensive.

And even top rated flash drives should never ever be the only copy of anything.