I have a problem with that. I've read the guidelines. You only accept stories that are family friendly; and that's not what I write. I'll try and write something slighty family friendly and post it.
You don't need to post the whole story -- in fact we usually advise against it -- only, say, the iniital 500 words. That will give us enough to go on in the first instance.
Does the unfamily-friendly crop up in the first 500 words? If not, then you're good to go.
If the unfamily-friendly in the first 500 words amounts only to four-letter words, then use asterisks judiciously -- eg f**k, or s**t -- and you're still OK. (Though the c-word is never acceptable, even with asterisks.) However, it's worth bearing in mind that the more such words are used, the less impact they have, so if there are more than a couple inside 500 words, I'd suggest you row back on them anyway, unless you plan on writing something like Trainspotting.
If, however, the unfamily-friendly within the first 500 words is excessive over-the-top violence and/or explicit sex, then to be frank it's highly likely we've found the reason why you're getting rejections.
In any event, before firing off more submissions, I really do think you need disinterested feedback on your work, so do try and put something up soon.