It sounds as if it's dry. Make sure you keep it well watered until it's re-established.
Others will have more solutions, I'm sure.

I've got a few questions for you, and a guess at what might be wrong. First, though,

1. where is it planted - in a sunny spot?
2. Is it planted against a wall or against a fence?
3. If its a wall, is it an old, crumbly wall, or a newly built one?
4. If planted against either of those, what's the distance between the plant and the wall or fence behind?
5. When did you dig up and replant it?
6. Did you add anything to the soil when you replanted it?
7. What part of the UK are you in?

And now the guess - it might be aphid infestation causing the buds to drop, or possibly a mildew infection, but hard to say without knowing the answers to the above.

Thank you for your answers. It isn't dry . It is against a fence about 10-11 inches away from the fence. I live in north Yorks. I have checked it carefully and cannot see any green fly on it. It has been in its current position 3 years. I have tried everything I can think of to get it to flower properly. My daughter in law has a plant which she doesn't do anything with and it's covered with flowers.

Thanks, but can you answer 1 and 6 as well please?