HDFC Bank — refund done by aliexpress but amount not credited in my account

Hi,
I had received refund from aliexpress.
They have provided with arn nos too stating refund is completed by i have not received the credit in my account.
For 16 orders refund is completed but not received any amount.
I have arn nos for 14 refunds. For 2 refunds aliexpress told me that bank has not issued.
Bank has no way to contact them for these refunds.
What should i do pls help me.