The amount of withdrawal does not match!

There are more than 1.9 billion coins in total, 1.7 billion coins have been withdrawn to the account, and 1.5 billion coins have actually arrived! I contacted the customer service and told me that I have been deducted twice on chain, and the handling fee + other fees. I only need to be on the chain once and I can get it. Why do I have to pay for it twice on the chain! What a rubbish exchange!