Been there, had enough, most of the guppies were imported and full of desease, love them to bits, but couldnt take it any longer of never having them very long, was always ill even in good water quality,Plus they fetched internal parasites with them.
I have a quarantine tank now.
It was so frustrating and wasn't worth it in the end.
If you really want to keep them i would find a good breeder of them, as the lfs ones are just not worth buying.