Have ridden (but not extensively) the Raleigh Companion.
The components are low-level and the wheels definitely are not quality or rated for more than casual tandem usage.
It is a low priced introductory twicer a notch above the department store quality.
However, the dealer should make necessary repairs/replacements under warranty.
Because a bike shop sells an occasional tandem that does not mean they and their mechanics are tandem savvy.
Get a hold of the Raleigh rep and persue it from there.
In the meantime, don't give up on tandeming.
Most of us started out with less than stellar 2-seaters and worked our way up.
Our first tandem practically ate spokes and we destroyed at least a couple rear hubs . . . that was 35 years ago.
Pedal on!
Rudy and Kay/zonatandem