During the broader New Year’s Eve weekend, a few things became more expensive and harder to get: restaurant reservations, for one. Sitting space at the bar, for another. But at least one mobile app-based service may have gone a little over the top...or a little Uber the top, as the case may be.

San Francisco-based start-up Uber, which allows users to summon car service via the Uber app on their iPhone (News - Alert) or Android-based phone (or via text message for other phones), found itself highly in demand on New Year’s Eve.

Regular customers, who are accustomed to paying a base fee of $8 plus $4.90 per mile in the city ($3.25 in the suburbs) and an additional $1.25 per minute time fee, found themselves paying considerably more than that on New Year’s Eve.

Though customers were warned in advance that there would be holiday surcharges involved, many did not expect to find charges as high as $100 on credit cards for rides they summoned on New Year’s Eve.

Some customers were quite irate about the sky-high charges. To pacify at least some of them, Uber is reportedly refunding some customers for the premiums they paid. Business Insider spoke to company CEO Travis Kalanick, who explained, “There’s no broad customer policy — more of a one-off thing for a few customers with unique circumstances: a few with no notification, some with drivers that may have taken the wrong route, etc.”

Uber operates service in its native San Francisco, along with Palo Alto (News - Alert), New York, Seattle, Chicago, Boston, Washington DC and Paris, France.

This isn’t the first time Uber has gotten the hairy eyeball from some in San Francisco. In June of last year, San Francisco’s taxi drivers went on strike. Uber saw an opportunity, and temporarily reduced its rates by 50 percent.