My car does not go in drive, automatic transmission slipping after fluid change

Hello, I have had this conversation hundreds of times, so I will spare you the technicalities, and simply deliver the bad news. The transmission will require a rebuild or replacement. Most often the maintenance is neglected for the transmission until something seems wrong, and by the time the transmission fluid is changed, the damage from neglect has already been done. Hopefully this will help dispell the rumor of transmission fluid changes killing transmissions. The flip side of this, is the wrong fluid may have been used, and, especially with automatic transmissions, it is imperitive to use a brand approved by the manufacturer (OEM). Do you know what fluid was used?