if you go to gallery and press the 3 lines at bottom corner (I believe) it should come up with a list of options, 1 of them will say Recycle Bin. just tap that and your in! you can delete individuals or the lot by pressing empty at the top.
also if you go to settings and search recycle bin (normally under the heading File Settings) you can opt to turn it off so things just delete immediately rather than store for 30 days in the bin. I think anyways.
oh sorry, it appears there isn't a way to stop this or delete them as of yet, I've scanned through lots of websites and forums and found this to be the common answer. some have suggested switching to Google messages app to bypass this. sorry I can't help more