Translation:I bought new dresses for myself while I was in Ankara.
I'm sure ''I bought myself new dresses while I was in Ankara' should be accepted.
If "I bought myself" is followed by a noun phrase, then it means the same as "I bought for myself".
(My Turkish is not good enough to recognise whether "kendim aldım" ever means "kendim için aldım".)
Isn't "kendim aldım" "I myself bought" (i.e. I bought them, not anyone else) rather than "I bought myself" (i.e. I bought for myself)?
I understand "I bought myself" (in English) only as meaning "I bought for myself". Since you can say "I bought her a dress" but you cannot say "I bought me a dress" and it has to be "I bought myself a dress" instead.
I cancelled the dislike to your question. It is now back to zero.
"Ankara'dayken kendim için yeni elbiseler aldım." Translation: I bought new dresses for myself while I was in Ankara.
Why is 'I bought for myself new dresses while I was in Ankara' not accepted.
Your English answer would be understood as spoken English to the Turkish question.
I will use your English answer as a new question & give it a Turkish answer.
"I bought for myself new dresses while I was in Ankara." -->
Ankara'dayken kendime yeni elbiseler aldım."
I used the dative case suffix "-e" for (kendim + -e)
To give the meaning (to myself)
Just the word order being ever so slightly different makes a difference.
You wrote "for myself" first & Duo's answer "new dresses" is before myself.
Splitting hairs. I like your answer anyway.