If you wish to complain online to the BBCs website:

 When Anna Watson of the Arnica Natural Parenting Network complained the reply was returned as quick as you could say “No conflicts of Interests” with the opening line “Firstly, we’d like to reassure everyone that no programme on CBeebies receives commercial sponsorship of any kind.”
However it did state that: If you are not happy with your reply you should escalate it to level 2 with the BBC and then level 3 and also complain to OFCOM and the BBC trust.