Dear Best Buy,
If I was a manager at your store I would institute a policy that is there were two or more customers standing in the return line, I would have one of the employees who seems to be meandering around with nothing to do, open a second register. I think this policy would be more efficient and would provide better customer service.
It seem that this would be a better policy than the one you currently have which apparently is that another register will be open if 4 or more people are in line and the idiot currently at the register needs two employees and a manager to assist him because he he wrote a check and now want to return something but doesn't have a receipt.
Or maybe don't let people write checks at Best Buy.