I feel you.
The thing is that Rock crabs is a bot hotspot so there are higher probabilities of you being banned there than being banned killing ghosts in varrock sewer.
Try doing more quests and skills so the account loots better, get some people in friend list join a cc, play the account for a few days.
Once you start botting try doing something else every few hours. Like buying items/selling at ge, getting a few levels from a skill or a quest to continue.
Because why would a new account/player get instant member and play 14 hours a day and do almost no extra things besides rock crabs?