New Thor ACE Motorhome r

We purchased a new ACE Motorhome 4 months ago. Overall, we are happy with it but have been having a difficult time with the radio. It said that it was " XM ready." We took it to an installer and he couldn't find the tuner and antennae. My husband called Thor and was told to get the kit which would adapt the radio to satellite radio. He then called Sirius Radio and they told him what was needed. He ordered the kit for $75 and took it to the installer. The antennae was installed but when he tried to connect the tuner to the radio, the plug pin pattern didn't match. My husband called Sirius again and they said to take it to Best Buy because they are partnered with Sirius. We called Best Buy and they said that we do have the correct tuner. Any suggestions? I would suggest to Thir that they just install the tuner and antennae and charge a bit more.