Here are the postal and email contact details for Primark HQ.
Primark Stores Limited
Primark House
41 West Street
Reading
Berkshire
RG1 1TT
[email protected]
I'd like to say I'm surprised to see something so blatantly sexist on the website of such a major retailer, but sadly, I'm not. However, unless consumers let them know they aren't happy to spend money with a firm intent on limiting children's choices and aspirations through their marketing, they'll not see anything wrong.
It might be worth referring to their Equal Opportunities Policy, which refers primarily to employment but should also relate to their supply of goods and services.
They also have a Corporate Social Responsibility Policy (in skeletal form on their website) which should also cover their responsibility to communities within which they operate.
Thanks OP for raising this. There have been many examples of companies that have withdrawn or re-thought advertising and products/services they carry because complaints were raised, so it's always worth at the very least an email to let them know you aren't happy.