Very possibly you are overwatering it. They like to dry between the waterings.

Depending on what condition your plant is - you can try to dry it up.

If the roots are totaly gone - you can try to pull it gently - if they are gone - you will get the top of easily. if it is the case - try to cut all the rot from the stem, trim big leaves and root it again - if it is a big plant - you will end with several "cuttings". They root OK from these cuttings - use barely moist soil - very light - 50% perlite
at least, pin your starter to the soil - you can use a half straightened staple, and bag it or cover with a plastic dome.

The main recipe for them - loose soil and moderate watering. Means - cut your violet soil in haf with perlite - and your watering in half as well.

Good Luck

Irina

Don't forget, they also like cooler temps. Probably not what's causing your limp leaves, but still...

Below is a link to a web site specifically for Streps; the wonderful people there will no doubt be able to help you to help your Streps thrive.

Good luck and have fun.

Korina

Here is a link that might be useful: Streptocarpus