Hard drive storage capacity has shrunk

[ihatepcs]

I have a Dell Inspiron 530 with an Intel Core Duo processor, running Windows xP Home, SP3. The original HD capacity was 320 GB.
One day, I noticed that a folder containing 30 years of photos was gone (not backed up). Determined that this not happen again, I got a Western Digital 1 TB external HD.
After hooking it up, it caused serious problems (frequent BSODs, freezes, crashes, etc.) I had to disconnect it, but the damage had been done.
I brought it into a local computer repair facility, they checked out the machine, and recommended to wipe the HD (after saving my remaining files), and re-install the Windows operating system. I agreed to this plan.
I got the machine back and it seemed to be operating as expected. Some days later, while re-establishing my preferences, I called up the C drive's properties. It showed a 149 GB capacity. Thinking that they'd partitioned the HD during the repair, I checked Control Panel > Administrative Tools > Computer Management > Storage. The HD was, apparently, not partitioned. It now had a total capacity of 149 GB. I called the repair facility and asked them why they'd replaced the original HD. They denied that they'd done that.
Was I lied to, or is there something I'm missing here?

[mr_spokk]

Take the drive out and check the capacity size on the label

[pcimage]

Take the drive out and check the capacity size on the label