Amber Windows has been served a £50,000 fine from the Information Commissioner's Office (ICO) after making nuisance phone calls.
The ICO received 524 complaints from people registered with the Telephone Preference Service (TPS), about the West Midlands-based company between May 2011 and April 2013.
After an investigation the ICO found that Amber Windows had been making unsolicited marketing calls to people registered with the TPS and handed the company a £50,000 fine.
Amber Windows was also given an Enforcement Notice ordering it not to call people who had previously told the company not to call or people who had not consented to marketing calls and were registered with the TPS.
Companies are prohibited by law from calling people who have registered with the TPS by The Privacy and Electronic Communications Regulations.
ICO director of operations, Simon Entwhistle, said: "This fine shows companies running marketing campaigns cannot plague the lives of people who have expressively asked not to receive unsolicited calls. We wrote repeatedly to Amber Windows asking them to stop, they ignored us.
"We will continue to target these companies that bombard households across the UK with nuisance calls and texts."