Silent calls, spam calls and ping calls galore (33 calls in 4 days)

This company is like a stalker or a bad ex that just won't give up. I have to-date received 33 calls from this company in the last 4 working days. I absolutely despise this company's practice as these people do not let up even after I put my number on the national opt-out list because of callers like them. I have blocked them on multiple numbers, used Truecaller to filter out their calls, but they keep calling from alternative numbers.

When you do answer the phone, you hear extremely loud noises in the background (sounds very jolly and not at all like a professional corporate company) and after several seconds the line dies out. Or the alternative, the annoying ping calls that end the call immediately when you answer to try to get you to call them back.

Please leave me alone, I am not interested in your company because of the way you handle business and I am with another company. Take the hint and move on with your business.

The numbers are as follows:

*** - 10 calls in the last 4 working days *** - 9 calls in the last 4 working days *** - 9 calls in the last 4 working days *** - 5 calls in the last 4 working days