Did you dead head it? are you watering? Feeding it? did you prune it at all? Is there any new growth showing?
I can find nothing about a rose names nemesis. Where did you buy it?
Most roses do not bloom through out the summer unless they are hybrid tea roses....and since I couldn't find anything about this rose on the web, I don't believe that is so.
Dead head it.....feed, water and you may be rewarded with another flush of bloom in about 2 or 3 weeks....but there is no guarantee.
Linda C

Do you mean nemesia instead of nemesis? There is a nemesia 'antique rose sachet'. I've had n. 'Innocence'. They are beautiful flowers, but they don't like the heat. The ones I had in early morning sun, about 3 or 4 hrs, did the best during the summer, but even then, they didn't bloom much when it got hot. They did start up again in Sept. Is it hot by you? Are they in full sun? If you have them in full sun, or afternoon sun maybe you can move them to a cooler, shadier area. Don't let them dry out either. You can try clipping them back alittle too. That may help get them going again. I gave up on them after 2 summers.
Good luck with yours!

Kat