Just to let the community know about my experiences:

Last week I used the implemented "swap" function within myetherwallet to get some ETH with BTC.
They partnered up with changelly for that, so I thought it's trustworthy and made the transfer.

Due to a bug in changellys system (didn't update to the new hash after a "replace by fee" for a quicker BTC transfer, it took me a week to reach them (they didn't response to my emails).

Yesterday I found the chat function on their homepage and seemed to get all matters sorted out.
I was wrong.
22 hours later I AGAIN emailed them to ask what's the holdup.
Their answer: "It takes 20 working days"
Sorry, but WTF?
It's their mistake, and still they have the NERVE to keep my USD 1500 for another additional month?

Using changelly certainly was a one time mistake for me.
I'm letting you know, because I whish somebody would've told me before....