As the constantly traveling head of a San Diego investment fund, Shubhayan Mukherjee looked forward to the free breakfasts, room upgrades, and late checkout that came with his elite status in the Starwood Hotels & Resorts loyalty reward program.

That all ended last summer, he said, when Starwood’s perks were folded into a new loyalty program by Marriott International, which acquired Starwood in 2016 to form the world’s largest hotel company. Called Bonvoy, the combined reward program has 125 million members, more than any other hotel loyalty operation.

"Suddenly, everything went downhill," Mukherjee said.

Marriott representatives acknowledged via email that the new combined reward program has been plagued with problems, including members who haven’t been able to get room upgrades or free nights they’d earned. Marriott is investing in technology fixes and increased hiring and extra training for call-center workers to fix the program, the representatives said.

But Bonvoy members, who book some of the world’s most luxurious hotels, are not waiting patiently. Many are protesting online.

Mukherjee, who joined the Starwood program in 2000, was so incensed about Bonvoy’s failures that last month he helped create a website (Bonvoyed.com) where members can air their gripes. The site already has more than 600 entries.

His Bonvoy problems began, Mukherjee said, when he traveled to Russia last summer to see World Cup games and found that he couldn’t get his usual free breakfast, among other perks.

"They still don’t fix anything," he said. "Nothing has changed."

After the $13 billion acquisition of Starwood, Marriott replaced three loyalty reward programs — Marriott Rewards, Ritz-Carlton Rewards, and Starwood Preferred Guest — with one program.

The Bonvoy program lets members of all three programs collect points under a single points currency when they stay at any of 6,500 hotels under 30 different brands in 127 countries and territories.

Not everyone is upset about the Bonvoy rollout.

Joe Brancatelli, who writes an online column on business travel and is an elite Bonvoy member, said the program has worked well for him. He also dismissed the 600 complaints on Mukherjee’s website, saying they represent a fraction of the millions of members who use the program.

"The complaints ... do unquestionably point to some systemic issues," Brancatelli said, "but, man, the numbers are tiny compared to the member base."

The new program’s name seems to be a play on the French expression bon voyage but online critics have turned it into a disgruntled verb and hashtag: #bonvoyed.

"I just spent 21 minutes on the phone trying to transfer points because I couldn’t figure out your website, then the agent hung up before finalizing," one Bonvoy member tweeted. "What more could I do? #Bonvoyed."

Another Bonvoy member, who described himself on Twitter as a "marketer and beer writer," tweeted his frustration about requesting records of a hotel stay and getting a reply 24 days later instead of the three to five business days promised by Bonvoy.

Marriott representatives say they are taking member complaints seriously.

"We are actively fixing the issues and we are committed to getting it right for our members," Marriott spokesman John Wolf said in an email.

In October, Marriott chief executive Arne Sorenson described the problems with Bonvoy during a media event as "noise around the edges." But as months passed without improvement, he acknowledged that the problems were frustrating members but promised the glitches would be ironed out quickly.

Sorenson last month boasted that the "cost of our loyalty program is the lowest among our competitors in the hotel business, while delivering the highest value to guests."

"No longer will customers have to go through the step of having to transfer points from one program to another in order to redeem," Sorenson told analysts during a conference call about earnings. "No longer will they have to think about whether they’re meeting their elite night requirements by getting enough nights concentrated in one program or another. It’s now much simpler."

But it hasn’t been so simple.

“The integration of our legacy loyalty programs was complex,” Wolf said when asked about the cause of Bonvoy’s difficulties. He added that glitches are expected “when any company introduces a new product or service.”