Q. I booked a cruise on the Star Princess about 18 months in advance. A few months later, I called to upgrade to a suite. A Princess representative quoted me a price of $1,449, and I paid the additional amount that day. My confirmation sheet showed my cabin and stated “paid in full’’ with a balance of zero. It also noted that I was entitled to suite benefits, like accessing the Sanctuary and specialty dining.

The trouble started when I tried to make dining reservations. The website tried to charge me for things that should’ve been included. I called for help and ended up making more than 20 calls to various departments. During one of these calls, an employee told me that I hadn’t been charged enough for the upgrade and wouldn’t get the benefits unless I paid more.

Later, I discovered that Princess had added $3,967 to my booking without my permission. When I called to protest, the cruise line gave me an ultimatum: pay the extra money, move back to my original mini-suite with a refund of the upgrade fee, or cancel my cruise entirely. I even offered to give up the suite benefits just to keep the cabin that I had paid for, but they refused.

I feel like I was bullied and threatened into releasing my suite. I’ve reached out to customer relations and corporate management multiple times but received no response. I am a Platinum Cruiser and have never been treated this way on the 70 cruises that I’ve been on before. I want the suite I paid for at the price that I was quoted.

DEBORAH KECK,

Sunnyvale, Texas

A. Princess should’ve honored the price that it quoted you and confirmed this in writing. When a company sends a document stating that a booking is “paid in full,’’ this is a contract. It shouldn’t decide later that it made a math error and demand that you cough up another $3,967 to cover its mistake.

Most cruise contracts have clauses that allow them to change prices due to fuel surcharges or government taxes, but they don’t usually include a “we forgot to charge you enough for the room’’ fee. Under basic contract law, once there’s an offer, acceptance, and payment, the deal’s done.

You did the right thing by keeping all the paperwork. You also attempted to resolve this through the proper channels, contacting customer relations and even executives at Princess headquarters (whose information I publish on my consumer advocacy site, Elliott.org).

I’m deeply concerned about the lack of response from the cruise line. You contacted Princess multiple times for help, but you say that no one responded. My team followed up several times about your case, and I also contacted Princess on your behalf. The response was nothing.

It’s a disappointing result. Despite multiple inquiries, Princess refused to provide a resolution or even a comment on why it added $3,967 to a confirmed booking. This left you with one last option: You could’ve taken your case to small claims court. I should note that you’re a Platinum-level customer, which means you’ve been on a lot of Princess cruises. You’d think that the cruise line would be bending over backward to take care of you. But apparently not.

You accepted a downgrade to your original cabin and didn’t pay extra for your cruise, which wasn’t exactly the resolution either of us were hoping for. Come on, Princess!

Christopher Elliott is the founder of Elliott Advocacy (elliottadvocacy.org), a nonprofit organization that helps consumers solve their problems. Email him at chris@elliott.org or get help by contacting him at elliottadvocacy.org/help.