If the growing tips are damaged, you might as well cut them off, since they won't bloom this year. More leaves will develop later, and feed the flower buds for next year. Be sure to feed them regularly as long as they have leaves, since they will need the extra help to bloom next year.

Don't cut back into any live stems at this time - just the dead stuff as tugbrethil suggests. I usually cut these down in the autumn once flowering has finished and the stems have died off, but as these are new plants I would leave them until they have established over the winter, removing only the dead branches if you really have to. Otherwise, when the new growth shows at the base, in the spring, cut them down then.