Q.Clematis
Have got 2 clematis in my garden. Cannot get them any higher than 3/4 feet. What am I doing wrong?

Do you know the variety that you have planted? There are many cultivators and their are compact varieties that are meant to stay low.
Check the planting location. A soil test can help you determine if the plant is lacking nutrition.
Here are some links with more information.
https://www.gardeningknowhow.com/ornamental/vines/clematis/growing-clematis.htm
https://www.gardeningknowhow.com/ornamental/vines/clematis/pruning-clematis-vines.htm