This happens all the time. I`ve seen more than one guy say he got flowmasters when what he really got was the cheap copy cat of the flowmaster. Every FM I ever seen has the name on the case. The cheap copy cats have nothing on the case. Many exhaust shops pull this scam, you pay for flowmasters but you don`t get them, instead you get a cheap copy that sounds almost identical. This one moron I seen out of town paid for flowmasters and the guy installed glass packs, and the owner didn`t know the difference and I didn`t have the heart to tell him how bad he got took.
In the world today the rule is what you don`t know can hurt you.