Some months ago I had a number of similar calls. In fact, on 36 consecutive occasions, over a period of 18 months, I got -

"Please stay on the line for an important message."

After about 40 seconds, I got

"We're sorry, all our representatives are busy. We'll try again later."

In addition to the 36 calls I received, and held to try to identify these assholes, other family members picked up on additional ones and just hung up after a few seconds when noone came on.

After 18 months, they finally found a representative who wasn't busy, and learned that they were calling the wrong number.

They were a bill collection agency, who supposedly are allowed to call but not to harass. If 18 months of ringing my phone with no intention of speaking to me isn't harassment, what is? (Even if it had been my bill.)

Incidentally, they refused to identify themselves when they learned that they had a wrong number.

John