Rose Bush

I am surprised that you haven't had an answer from one of the USA members. I don't know about your climate, but over here, I would advise waiting until the rose is dormant and then pruning it half-back and re-planting. Get as much of the rootball out as you can. Make sure it is well-firmed in. Prune again and give it a good feed in the spring and it should take off again!