Bill and Mary Lou Haas were looking forward to a peaceful European river cruise booked through Vantage Travel during the Christmas holidays. But their expectations were figuratively shattered when they found several unexpected guests would be joining them on their vacation: kids.

“One of the clauses in our cruise contract states that the cruise has no accommodations for passengers under the age of 12,” Haas told me. “However, upon arrival at the Amsterdam airport, we found out that there was an extended family with four children as young as three that were traveling with us.”

Needless to say, even the best-behaved kids can ruin a river cruise. Unlike the larger ocean vessels where young passengers can be sent to an arcade or play area, riverboats are small and intimate. (We left our then 18-month-old toddler with his grandparents when we went on Danube riverboat cruise a few years ago, a decision we didn’t regret when we saw how small ship was and how well noise traveled.)

Haas and several other passengers spoke with a cruise line representative at the airport, reminding him of the no kids rule.

“His only answer was that it was a corporate decision and left us no other option,” he remembers.

You can probably imagine what happened next. The Haases reluctantly boarded the vessel, and for two weeks, their holiday riverboat cruise resembled a playground. Children were running around the ship, laughing and yelling.

Bottom line: the passengers didn’t get the adults-only cruise they’d booked.

When the cruise ended, they complained to Vantage, but the company will do little more than admit that its “no kids” rule had been bent.

Complaints and request for a refund of the cruise portion of the trip have fallen on deaf ears.

They readily admit to violating their end of the contract, saying it was a consideration made for the holiday season.

They refuse a refund and have offered a $1,000 per person credit for my next Vantage cruise.

Haas wonders what would have happened if he and his wife had violated the Vantage contract — say, by bringing a pet. Would the company had denied them passage? Probably.

“The travel credit is a joke since I never plan to travel with Vantage again,” he added.

Is the $1,000 cruise credit enough? Or should I push Advantage to refund Haas’ entire cruise?

I’m conflicted about this. From Haas’ account, it seems clear that Vantage violated its own “no kids” policy, and a $1,000 cruise credit is a nice gesture. But nothing says “I’m sorry” like a partial refund — real money being sent back to an aggrieved customer.

A cruise credit, on the other hand, says, “We’re sorry for the way we made you feel.”

I think Vantage should pay for breaking its own rules. But I’m not sure I can advocate for a full refund, because after all, the Haases cruised for two weeks, enjoying food, service and fabulous European ports of call. Had Vantage denied them those amenities, then I might be more comfortable pushing Vantage to offer the couple a refund.

Then again, Vantage didn’t give the couple the cruise they thought they’d bought. Isn’t a refund an appropriate penalty?