No message, so assume a caller trying to sell something

Caller: Digital Design World

Digital Creative World. They use the telephone number (02) 8552 ****. When you block the number just called, they call again a few days later with another same number but the last one or two last digits changed. You block each number after each call but the pattern keeps repeating. Phone states Potential Fraud when it rings. A search of the ASIC business and company registers finds no evidence of registration.