Non-stop bugging

I have received many calls from the telephone number ********** over the past few days. Whenever I answer the call, there is silence and then the call is dropped. This is very annoying!!

I tried phoning the number and the voice recording says something about "welcome to our call quality....centre...". According to TrueCaller (which I have found to be very accurate) the number belongs to ECN Telecommunication (Pty) Ltd .

First of all - where did they get my number from? Secondly - it is very annoying to receive so many calls from this number and when answered, the call is dropped.

STOP BUGGING ME!