Phone call harassment

I have a loan with Capfin that I have been struggling to pay due to being laid off work. I have made payment arrangements with them, my issue is they keeping calling my cousin everyday countless times and she has expressed that she would like them to stop mainly before we don't live together and they can always call me, but they never call me. This has reach a point of harassment. I called them and asked who gave them my cousin number and I would like them to stop calling cause it is an inconvenience to her, they denied harassing and still to this day keep at it. She is even thinking of taking legal actions. This has also caused a problem to our relationship. It is so unprofessional of Capfin.