The only way to make them stop is to make it unprofitable for them. If we all answer and waste as much of their time as possible, it won't be profitable.
They are trying to evade call-blockers (which hang up after one ring) and answering machines and/or voice mail (which stop the ringing after a customer pre-set number of times).
this is computer generated system that calls you and hopes you answer. If you do then it records that this number belongs to someone that actively answers their phone and they will sell your number to other jack wagon solicitors! Key Point: Do not answer your phone if you do not recognize the number!