Insistent phone calls

I find it really strange that I have closed Edgars account and have told Edgars to stop phone me. This week alone I have had 18 phone calls from Edcon in 4 days ! I had to block the number yet I still shows the call log attempt. I have no dealings with them. Initially when I did answer there was no response. This is becoming harassment especially when I Google the number it came up with a complaint with the same number!! when I don't answer the call a different number tries. This is pathetic.