Posted: 11/08/2015 at 16:09
It looks like you have some problems there. Rose sawfly and blackspot. Add to that a bit of bad dead heading and a non specialist fertilzer plus a distinctly small pot.
Remedy, repot using John Innes No3 into a pot double the size. Feed with ROSE fertilizer, spray the whole plant, flowers and all and stem and surface of compost with rose clear. Pick off all the affected leaves, water well, Prune back flowered stems to a leaf axil, whilst trying to maintain the shape. Leaves will grow back, and water weekly with a drench, and leave a good inch between the lip of the pot and the surface of the compost.
You may get a good flush of flowers if the weather is kind.