Repair shop installed wrong version of Windows 10

My desktop computer began having problems that got worse and worse until I could do nothing at all on it. So, we took it to the shop for diagnosis and repair. It took over two weeks to finally diagnose the problem as a failing hard drive because it kept passing all their diagnostic tests. Once they knew the problem, replacing the hard drive was easy. Of course, it's taking me longer than I like to get all my programs reinstalled (a tale for a different day). So, this afternoon, I discovered that the repair shop installed Windows 10 Home when I specifically told them I had Windows 10 Pro on my computer.

Naturally, I plan to contact them in the morning and ask why they did not install the correct version. In the meantime, any suggestions for getting Windows 10 Pro on my computer without having to pay for an upgrade? When I originally upgraded to Windows 10 Pro, I got a PIN and a Security Code. And I have the original product keys from when I upgraded to Windows 8 Pro and Windows 8.1 Pro.

Thanks.

The cheapest route would get the shop to upgrade it to Windows 10 Pro for free.

FWIW, here's Microsoft's instructions: Support.Microsoft.com > Upgrade Windows 10 Home to Windows 10 Pro