Hb Services — harassing phone calls

They call my office several times a day and several times a week. Last week, they called over 40 times. They will not remove my office number from their phone call list. I am being harassed by this company. They refuse to give me a call back number. They hang up on me when i ask them to stop calling. They give their first name only and no official information. I have no idea what they are actually calling about because of the language barrier.