Consumers are being urged to ask for refunds if they are overcharged for ridesharing services in the wake of a number of complaints about the businesses.

The use of ridesharing services - an alternative to taxis - has exploded in recent years.

But some people using the services are being charged much more than they expect.

In one case a Christchurch man was told the estimated cost of using Ola for a 10km trip was $23 to $25 but he ended up being charged $77.

When the man complained the company refunded him $6.49 claiming there was a high demand at the time of the booking which saw the high fare.

In another case an Auckland customer was chased by Ola for $148 over a ride estimated at $25 to $30. When threatened with a $44 debt collection fee, he paid up.

Both customers were denied full refunds when they spoke to Ola but after Consumer New Zealand got in touch the company refunded both customers the extra they'd paid as a "gesture of goodwill".

Caitlin Cherry, Consumer New Zealand head of content, said consumers shouldn't be facing any surprises regarding how much they are charged at the end of their ride.

"These services provide an indication of your fare upfront when you book."

Cherry said anyone overcharged, or charged for a fare they didn't take, should request a refund.

"If you're refused, request a chargeback from your bank. Ride-share companies should be transparent with passengers about the cost of their services."

Since November 2018, the Commerce Commission has fielded 76 complaints about ride-share companies. Most were about pricing and advertising claims.

Ola had 39 complaints, Uber 36, and Zoomy had one.

In 2019, Ola received a letter from the commission, outlining complaints alleging behaviour – including  over-charging  and  discounts  not being honoured  – that risked breaching the Fair Trading Act.

Ola and Uber have also  attracted the  attention of  Waka Kotahi  New Zealand  Transport Agency (NZTA)  over  complaints about driver behaviour.

Regulations require  drivers carrying fare-paying passengers to pass  both  driving and  criminal history checks.

Of 320 complaints  since 2019, 60  were serious enough for NZTA to revoke or suspend the driver's  passenger  licence.

Forty-one  of the 60  were Uber drivers  while  13  were  driving for  Ola. The remaining six were  Zoomy  drivers.