When i send bulk txts to people they weirdly get sent as picture messages on my note and i end up getting charged 25p each. I send these txts the same way i always do without getting charged. is there a way i can turn this off??

Pretty sure you can't. Have the same issue on my Note and, I think it may be on all Galaxy phones. Larger text messages get treated as MMS ones. So, either split the messages or perhaps use Whatsapp or equivalent messaging app. I use Whatsapp for all picture messaging.