The working tax credit fiasco -- where thousands have been unable to contact the constantly-engaged special helplines -- has taken a new twist.

The new scheme is already under fire for the huge delays many are facing in getting the money they are rightly owed.

But now it has become clear that the opposite is also the case -- some people are being paid hundreds of pounds more than they are entitled to.

Like those who are owed cash, they are also hitting frustratingly long delays in getting through to the helplines to try and rectify the errors.

And while their bank balances get bigger -- despite their efforts to get the payments stopped -- others, who are often in desperate need of the funds, are still facing agonising waits. One, a father-of-two who lives near York, was told he had been awarded £4,500-a-year -- even though the correct figure should have been £540.

"They simply didn't take my salary into consideration. They had me down as a zero salary and thought that the whole family was living on my wife's earnings," he said.

With the money being paid directly into his bank account, he desperately tried to contact the helpline for weeks in an effort to put things right.

"My big gripe was that I simply couldn't contact the helpline about it and I tried dozens of times."

In a second case a woman in Redcar changed jobs, filled in the relevant forms _ and then discovered her husband's salary had been rated as zero when almost £370 in tax credit was paid in one month.

"I was so stressed about it. I was getting up early in the morning to try and get through to the helpline without any success. At times I was on the verge of tears," she said.

Both finally got through to the line late on Monday afternoon -- but only after weeks of fruitless effort.

A spokesman for the Inland Revenue apologised for the problem. "For a spouse's income to be overlooked is very rare," he said.

"We do our best to minimise mistakes and spot them and put them right but given the volume of claims being processed, on occasion we will make mistakes in collecting the necessary information."

As well as trying the helping he said people could contact their local Inland Revenue office or write to Inland Revenue Tax Credit Office, Preston, PR1 0SB.