misleading information

this it's what happened I called CAR SERVICE CITY ORMONDE in February booking for a service, and i spoke to Ofentse. I asked if they were GM registered dealer as my car was still on warranty he said yes, now my car broke and I took it to GM for repairs that's when I found out that my car was no longer on warranty because the car was not serviced on an authorised dealer. GM warranty manager called again on Tuesday(07/04/15) to confirm if they are registered with GM and she was told the very same thing they told me that they are GM authorised dealer, then she ask for a certificate. On the same day i called them and they confirmed again that they registered with GM, as the GM has requested the certificate i then ask them to urgently send the certificate to them. then they send a RMI, when GM manager confirmed it with their HEAD OFFICE that's when they found out that they are not registered, then i called their CAR SERVICE CITY head office i spoke to Natasha, she confirmed that they are not registered. she said i should send her an email with the info. and she will investigate. So in a nut shell the information I got from ORMONDE wasn't true. so now for repairs i need pay R +- 8 000.