Lewd texts

ATT isn’t doing anything about them. They simply deliver the texts, they don’t read them or decipher their content. They have no idea the texts are improper unless you report them by forwarding them to 7726.

How does one forward a text?

That depends on your phone. 

I found instructions. Posting in case others need: https://www.wikihow.com/Report-a-Spam-Text

^^^^ that may help but it won't stop them altogether. Your information (phone number, email address, etc) is already out there and probably sold to countless scammers/spammers/phishers and it is almost impossible to stop them all.