Annoying Nuisance Call Centre

I keep getting calls from 084 145. When I answer the call, I get on hold music. I tried to hold to see if anyone will answer but nothing. Why are agents HARRASING multiple people at once, trying to see who will answer first, with the rest being on hold like idiots. I have 2 contract with Cell C. PLEASE don't chase me way as a Customer. Unless Cell C can give me a Samsung Galaxy S20 Plus with Galaxy Buds for R299 per month on a 2 year contract, which I know they cannot, STOP CALLING ME. I do not need data...I have uncapped 5G at home.

Now I'm forced to blocked all calls from which might be a very important number.