Parted Magic Secure erase running for 3 hours?

Well I'm returning a used hard drive with a lot of files back to Best Buy and I don't want them to have access to any files. I called them and they claim to "throw out" returned used hard drives but honestly, I doubt they'd throw out a perfectly working $250 hard drive. So, I downloaded and ran Parted magic Enhanced Secure Erase and it says the approx time is 306 minutes.

It's been running right now for 4 hours. I know it says it'll take around 5 hours but I've read on forums that it only took people like 30 seconds or something now. There's no "time left" clock thing, It's just a window that says a Secure Erase was issued and the approx. time.

Anyone know whether or not this is normal?

It's a 2 TB Western Digital Caviar Black hard drive.