Firstly, we can't blame the girl since it's her first day on the job. She also can't be blamed for not providing extras in a RNT shop. It's at the discretion of the girl whether she provides extras or not. If FS was requested then it may have been appropriate to visit a FS shop.

The messages (cut and paste here) between the concerned parties appear to have taken place after the session. It begs the question what was relayed to the customer before he chose the new girl. If the shop told him before the session commenced that their new girl certainly did extras only for him to find out later that she didn't then the shop is at fault. If this was not the case, then the customer has only himself to blame for failing to make inquiries with the girl at the beginning of the session if he was after specific extras.

Overall, it is the shop's duty to train their girls rather than sending them out without any training and knowledge. When a newbie starts and is not told about Parts 1 and 2, it's not her fault if the customer has an expectation that he will get extras and later complains that he didn't receive it. To state that it was the girl's first day is simply not taking responsibility for what has happened here. I guess both parties are at fault here.