Called twice today, can here it's a call centre

Keeps calling several times a day. I have answered it once and there was a long pause so i hung up.

I just received 2 calls within the last hour one at 5.32pm the other 6.38pm. They did not leave any message and I don't answer numbers I don't knoe.

Caller: I don't know

Called about 5 times in 2 hours today. I don't answer phone numbers I don't recognise. Won't stop calling and never leaves a voicemail.
Probably just the same scam company that rings me all the time and is constantly changing their numbers.

Answered. Nobody on the other end. Another time waster.