Missing Refund, how is this possible?

We are a company that bought numerous products with Dell. Recently we purchased a monitor and returned it (unopened). A customer rep confirmed the returned item and issued a credit memo. He said once a credit memo is issued it means a refund is on the way. 

Fast forward 30 days we have not seen the refund. I tried to call customer support but it is a disaster! Every single person on the phone will forward your call to another department. In one call I've been forwarded 6 times! and it will loop back to the same department. I've tried 3 times over the past week and can never get an answer.

I then googled dell missing refund and was shocked by the number of results that googled returned with the same people in the same situation! How could this be for a company this size and reputable? I'm shocked at how it's impossible to get an answer where the refund is. I think our last resort is to file a chargeback. This is a disaster and feeling hopeless.