Harrassing calls- 40 calls a day with no purpose!!

I had previously had an issue with the number of calls that I receive a day from First for Woman - Direct Axis. I receive +-40 calls either private or from a *** number, upon answering there is no answer and thereafter they call my work landline continuously and no answer from the. The other day I managed to answer one of the calls and the gentlemen tells me that he has no idea why he called(please refer to my profile). Can a call centre call 1 person with no reason +-40 times a day.Its ridiculous and invasive I have downloaded an app which records the number of calls and the caller as proof.