Plant ID Please

Hi, Got this from B&Q last October for 50p

But it never had a name tag or any label on the pot, it just started to flower in the last few days and well worth the 50p even without a name tag

 

Phlox Paniculata

 

Thanks...its grown quite tall, about 18 inches in hight.......Assume if you keep deadheading them then the flowers will go on to the first frost and you can divide in early Autumn or
don't they last into late October / November?