AC/DC fan Tamar McKewen was not impressed to discover her credit card had been maxed out with three times as many tickets bought than she was after, after a blip in Ticketek's online booking system for the band's Wellington concert.

A number of ticket buyers have complained about the overloaded system that either had buyers unwittingly purchasing too many tickets - or not able to buy any at all.

Tickets for the ageing Aussie rockers' January concert went on sale at 9am yesterday, but the massive volume of customers left many frustrated with faults on Ticketek's website.

However, Ticketek general manager Brendan Bainbridge said the day was a "success" and although he did not know the figures, only a small number of people were probably affected.

Ms McKewen said she logged successfully onto the website before 9am.

However, after she entered her credit card details and was waiting for confirmation from the site, the webpage timed out.

Ms McKewen was trying to buy three $160 tickets to the show.

She repeated the process two or three more times before a note appeared advising her to call Ticketek before attempting to buy any more tickets.

"But what I was worried about was, in Australia the tickets sold out so fast, I was worried I wouldn't have tickets at all."

Over 100,000 tickets were sold in Melbourne alone within 45 minutes, and over half a million were sold for the Australian tour in four hours.

Ms McKewen could not get through on the phone to any of the Ticketek office numbers.

"I spent the entire day ringing," she said.

Finally today she got through to a Ticketek operator who told her she had bought nine tickets.

The company would refund the cost of the extra six tickets.

Ms McKewen believed the site would have let her buy more had her credit card, which only had a limit of $1500, not maxed out.

"As much as I'll never use the Ticketek website again because of the hassle, I know it was all worth it to see AC/DC."

Mr Bainbridge said the site's webpage timed out for a number of people because the large volume of ticket buyers meant it was taking longer for the company to confirm purchases with credit card companies.

He said some people may have got an error message saying a problem with ticket purchasing had occurred and they should contact Ticketek.'

"A lot of people went back and repurchased and maybe repurchased a third time because they weren't sure it had gone through when it actually has gone through."