I mimicked your script and had success getting Case and Account data. I'm using QV 11.2 SR6 and connector version 12 with url to force API version 30.0. I only limited my data to the last 30 days though. I would say that its possible your Id field 'Account__c' in 'Account_BAN_Tax_ID__c' isn't? Make sure they are. Check to see if they're 15 or 18 characters.
Here's my code;
Where CreatedDate = LAST_N_DAYS:30;
Id as AccountId,
Where Id In (Select AccountId From Case);