i have sd card it has 128 gbs of memory. i delete pictures and other things on it but they come back the next i look at it on computer.?

SD card is locked? Can you still write to it? If not and the lock is physically off then it may be a sign of corruption. The card is already damaged and has locked itself to prevent loss of data. This gives you the chance to copy all your files from it to the computer or another storage device. If the card has already locked itself and you already got all your files safely, you can now throw away the card. There's no fixing it.

It could be that the card is write protected which would prevent file from being deleted.  Look at the little switch on the side of the card is in the correct position.

Normally you don't need to delete the files after downloading them to your computer.  Instead of deleting, simply format the card using the camera's format function.  This will clear out the file system's directory and the card will be clear.  

I always copy files from the card to my computer to ensure that if something goes wrong, a copy of the files are always on the sd card.  Only after confirming that the files have all been successfully downloaded do I format the card.  NEVER use anything other than the camera's format function to format the sd card.  Using any other device such as another camera or a computer will place a file system that is not compatible with your camera.  You would then have to reformat the card again using your camera's format function.

What are you doing to delete the files?  If you're deleting them in camera, what sort of camera is it?  Can you delete any files or do they all come back?  Is the card write protected?  Can you create and delete files on the card with your computer?