Sorry you didn't get what you expected.
If it is your contract and you only change the subscription, it can't be an under 26 bundle as the holder need to be under 26. The solution here would be a taking over of the contract on behalf of your daughter.
Regarding the inOne Avantage, it is not activated right away, but should now be activated.
I suggest you to go back to the same Swisscom Shop and explain the whole situation. They will be able to make the appropriate changes.
I can have a look too if you send me the concern number by private message.