Propane regulator

I filled two propane tanks at a gas station in a very small town several years ago. Both regulators on the RV, and the regulator on the camp stove stopped functioning within a few minutes of operation. My friend filled up at the same place at the same time, and his regulator failed also. Bottom line, the propane we purchased was badly contaminated. I don't know what it was contaminated with. We contacted the gas station and they said several folks had complained in a 48 hour period. They also paid for our complete system to be checked and the regulators to be replaced.