Going to need a bit more details than that. Do you have a transaction id so we can see if youve sent it to the right place and also to check youve put a large enough fee? Im not sure from your message but did you send ethereum or bitcoin to buy ethereum?
I have sent ETH to my Yobit wallet. Directly from Bitstamp. Thats my ETH adress on Yobit : 0x4b72676858558236d6e27519cdd07756377e263a
And i sent the ETH to this adress.
Thanks for helping !
Nowadays yobit is facing lot of problems in wallet when depositing it, even the staff wont give you much support so you have to wait long and even ETH network is facing lot of conjunction. Check with your Bitstamp admins about the transaction status.