My wife and I are (unexpectedly) expecting our 4th baby. We paid for a private scan at MUMS last week. Part of the package is a DVD of the scan. The scan was a really good one, but unfortunately when we got home we realised our DVD was completely blank.
I phone them up and they offered a free scan. I was still disappointed because there was a beautiful part of our previous scan that would be lost, where we were zoomed right into our baby's hand as she repeatedly clenched and reopened her hand, but I agreed because at least we would have something.
When we had our scan they gave us probably double the normal amount of time. In addition to that they upgraded our scan from a plain ultra sound to one of those 4D scans. We were given twice as many printed photos of the scan, and absolutely loads of still images were written to the DVD. They more than made up for the initial unfortunate mistake.
MUMS is a good company, because they are good when things go wrong!