Well its late in the year and once black spot takes hold, as the weather gets damper and colder, it is difficult to shift.

I'm afraid the best you can hope for is to control the problem, so this year, ensure you collect up fallen leaves from the soil (it overwinters there), leaving none behind, as they fall. Next year, after you've pruned them in March, wait till growth begins properly, usually around April, then start spraying with Roseclear Ultra fortnightly right throughout the season. Feeding the roses with something like Toprose in April and and again in June will help their resistance, as would a mulch of composted manure. There is an alternative method, but you'd need to spray weekly instead of fortnightly - use cow's milk in a ratio of one part milk to two parts water, doesn't matter whether its skimmed or full fat (better if its skimmed, less smelly) and spray till run off every week. Link below gives more info on this method - its an American article, but the basics are the same

http://www.agardenforthehouse.com/2012/05/got-black-spot-get-milk/

You need to start spraying for blackspot early in the season. I usually start spraying around early May, and thereafter every 3 -4 weeks or so. I don't use Rose Clear, but prefer a specific fungicide like Fungus Clear Ultra I find that works well for me and at the moment the leaves on my roses are still clear and healthy looking.