Ditto. I've just been charged over £5 for sending a group text to several people because it sent it as an MMS rather than SMS. If I want to send media to people I use Whatsapp which relies on a WiFi connection. Its not that it was a long message, just a few lines!

Not impressed that Textra assume MMS is free on everyones tariffs. Thinking of ditching it if there is no way to disable use of MMS, haven't found it yet (v3.33). Have set option to prefer WiFi if this might force the issue.