Using normal numbers to call then just dropping the call

I keep receiving calls from your company. Now you guys are using normal numbers, and when I pick up the phone call drops. This is very annoying and creates an uneasy feeling. I have been a member/client of yours for years, but this is bordering harassment. If there is something to call me about, at least say something instead of listening for 2 seconds and then dropping. Please stop this, this is one of the numbers that calls me: +27 (76) ***

Please stop this