Rather than digging up the vine now and replanting deeper, you can mound up the soil level to a more appropriate height. You don't say what type of clematis it is but a hard pruning - to the second or third set of buds above ground - is a good idea for at least the first two seasons anyway. Prune now then allow the plant to grow normally for the rest of the season.

Thank you gardengal. I did as you suggested and now I have several new shoots coming from every node. I planted this last summer, so now can I prune based on the type ( which I have written down but not here with me now) in the fall ?
I am "brewing" alfalfa tea for my roses. Will my clematis benefit from this as well?

Absolutely - clems love alfalfa tea.