You should remove it in my opinion. I had one clematis that was originally planted 6 inches deep. I built an 8 inch raised bed around it to put in a veggie garden. The clematis never came up. In your case 1 meter is about 3.25 feet deep. Add to this the original planting depth. There is no way the plant is going to push thru that much top soil.

Planting clematis deeply is a good thing and typically recommended. But 3' is too deep!! I would agree that it would be best to remove and replant at a more appropriate depth.