I think this number is from LA Fitness. They keep calling me too, and I never answer, so I googled them and LA Fitness came up. I don't think they understand that I'm not interested in joining, I've said no a couple times, and they still call me trying to recruit me.
Are you on the Do Not Call list? If you are, go to the Do Not Call site and file a complaint.
If you aren't, go register yourself, then file a complaint next time they call.
The site to register or complain is https://www.donotcall.gov/
They don't call from a call list so the DNC list doesn't matter when they call you. If you aren't a member, someone who signed with LA Fitness gave them your information.