It's not telemarketer. It's from collectcent looking for a delinquent accountee.
By law, they cannot contact the delinquent accountee's neighbors, friends and relatives.
This is another method of getting a hold of the person they are chasing after.
They only call a small number of people in one or two days then off for awhile. Does not make any economic sense if they are truly telemarketer. Also they are rude, if they are really telemarketer, even if you (the potential customer) not buy anything from them this time, you might buy something else from them next time, so why be rude to your potential customer. Does not make any logical sense to me.