outlook contacts continuously restore themselves

I decided to clean out my contacts in outlook, so I exported them all out to a .csv file and then I deleted all 1,200 of them (100 at a time, because apparently microsoft feels that any higher amount would be bad...).

Then I spent a few hours in excel combining, consolidating and deleting them down into about 600 contacts.

When I went back into outlook and clicked on people, to my surprise all 1,200 of my original contacts were right there again as if I'd done nothing.

I figured that some other device must be restoring (through some normal synching process), so I turned off **REMOVED** computers and phones that I've ever used to access outlook).

Then I deleted all of the contacts once more, this time using the OWA webpage with my local outlook completely closed.  Unfortunately, the exact same thing happens.

After repeating that process several more times last night, I shut down my laptop and went to bed.  I got up this morning, opened my local outlook app, clicked on people and there were no contacts there at all.  For about 5 seconds I was happy, until all 1,200 of them instantly popped right back up like a really bad joke or a dream.

Something either on my computer or (I suspect) on microsoft outlook servers is automatically forcing a complete restore of all my contacts.

Two side notes: 1) I can create/add and delete single contacts and those changes seem to stick, and 2) I can delete all contacts except a single one and that seems to stick, and 3) I can import my cleaned up .csv file containing 600 contacts back into outlook (with only the one single remaining contact in there), it says that all 600 contacts have been successfully imported, and then within minutes - all 1,200 contacts are back right where they were in the beginning.

The truly frustrating part about this issue (and most companies these days), is that IF the customers could possibly **REMOVED** about it so that we can simply continue to make and sell more stuff.  It's very sad