i keep getting calls from this number multiple times

I get these calls from this same number so to save my sanity I downloaded a silent ring tone for my cell phone and all spam calls I get I assign the silent ring tone to them, I list them in my contacts as Spam1, Spam2, Spam3...ect.

This way they can all all the hell they want to but I never pick up the phone because I do not hear it ring.
Makes them waste resources and eventually because I am not answering I eventually get dropped from the call list.

You can win at this game you just need to be a bit smarter than they and their computers are.  :)

The company is First Credit Services out of NJ. They appear to collect debts primarily for gyms. They've been calling me repeatedly, at home and at work, even though I've informed them IN WRITING that I dispute the debt, I demand verification of the debt, and they don't have permission to call me at work. Do NOT trust these people, they are flagrantly violating the law.

Sounds like you should be about ready to sue them and win for their FDCPA violations.

This number have been calling me reclaiming the debt I owned to a gym and they even reduced my debt and only want my debit card  to settle the payment so they keep on calling me all the time so I was suspicious about it do not trust them