A company that made 40 million calls about PPI in just three months has had its licence suspended.
Falcon and Pointer, based in Swansea in South Wales, used automatic dialling technology to make the calls.
An investigation by the Claims Management Regulator (CMR) found the firm had set out to "plague the public and rip off consumers".
Meanwhile the government has confirmed that a promised crackdown on nuisance calls will be in place by the spring.
The CMR said that Falcon and Pointer had coerced people into signing contracts without giving them enough time to understand the terms and conditions.
It described it as a "serious breach" of the rules, and stripped the company of its operating licence.
It had previously been warned about its practices by both the CMR and the Information Commissioner's Office.
"Falcon and Pointer has demonstrated the worst excesses of the industry," said Kevin Rousell, head of the CMR.
"This firm clearly set out to plague the public and rip off consumers."
"They ignored warnings by us and the Information Commissioner's Office, and today have had their licence revoked as a result of that wilful ignorance." he said.
Under new laws being introduced by the government, direct marketing companies will soon have to display their phone numbers to customers, so preventing anonymous calls.
Research for the Information Commissioner's Office (ICO) has shown that around 20% of marketing calls do not provide a valid caller ID.
Companies that do not show numbers will face fines of up to £500,000.
The government said the new rules would make it easier for consumers to refuse unwanted calls, and then to report them.
It will also help the ICO take enforcement action against persistent offenders.
"Being pestered by marketing calls is annoying at the best of times, and at its worst it can bring real misery for the people on the receiving end," said Baroness Neville-Rolfe, the minister for data protection.
"There is no simple solution to the problem of nuisance calls, but making direct marketing companies display their phone number will help consumers and regulators take action."
Since January 2012, the ICO has issued fines totalling £2m for nuisance calls.
In 2015, there were 170,000 complaints.
The Department of Culture Media and Sport has launched a consultation on the issue, which will close on 23 February.
Measures will be in force by the spring, the government promised.