I assume that you have not transplanted your roses to the ground and they are still in their original containers.
Rose in container needs more attention and watering. Water twice a week during hot and dry period. Mulching the rose well can save you a lot less maintenance.
Roses that you have bought might be brought up by intensive fertilizer to push flowering for better sales. I assume that you have bought it in big distribution. The rose problem you mention is a common wear off sign when they do not get their adapted intensive fertilizer. Unfortunately, we home growerS are unable to supply those intensive fertilizer. I suggest you to reduce the watering to twice a week with a deep watering each time. To help them to adapt to a new pattern of fertlilizing, you can use liquid fertilizer for roses that wilL react quicker in your case. Do not transplant them now, not until the roses stablize itself.
Hope it helps.