How do I keep photos on iphone, but delete off icloud

Not sure why this is so difficult to do.

I want to keep all photos on my iphone, but delete every photo off icloud (i.e. I don't want anything on icloud).

Had 2500 photos, deleted 500 to make room for update, so I should have about 2,000 photos.

Apparently after the update my phone started using icloud (got a pop up saying my icloud was full), I called Apple told them I don't want any of my photos on icloud, they told me to sign off icloud...I did but it deleted all my photos off my phone after Jan 22, 2017 (so I am down to 600 photos).

After 3 days and 8 different rep, my iphone is back to the 2000 pics I wanted (and the 500 I deleted are off) which is great...but we are back to square one.

What I am trying to do:

(1) Save these 2,000 photos on my harddrive (I saved/backed up about 2 months ago, so technically I only need to save the last 250 pics or so).

-I tried imagecapture on my macbook which is what I normally use to transfer photos, however it doesn't recognize the 2,000 photos, it just recognizes 600 (photos before Jan 22, 2017).

-I tried going to www.icloud.com but apparently Apple got rid of selecting a bunch of images, so I'd have to select the last 250 photos one by one if I want to save them (***?)

(2) Obviously I want to save the photos first, but after that I want to delete all photos of icloud. Despite what the rep said (sign out of icloud) it does not do it. Again, i want to leave the 2,000 photos on my iphone as is, but I want to delete all the photos off icloud.

Honestly it seems like pictures after Jan 22, 2017 are not saved on my phone and just saved on icloud so if I sign out, then it deletes them off my phone. I have no idea what is going on. Apparently no one in Apple does it. Is it really that hard to keep the photos on your phone as is and just don't have them on icloud? like wow!