I have been getting calls from this "church" for at least a year now. I lost count at around 30 but they call at least once a week. I started to save their numbers so I'd know it's them and just ignore it but they leave voice mails. So I gave them all personalized voice mails with "F**K off, any further calls will result with a call from my lawyer on grounds of harassment.." type messages. Still they persist. These people are rude. Picking up results in frustration regardless if your olite or angry with them. Nothing works. Im going to look into this call forwarding" thing and forward them to 1-900 numbers.
I went through the same thing with those idiots....... I know that they are VERY protective of their BBB (Better Business Bureau) ratings. If they bother you again, find out what org they are calling from, then file a report complaining of harrassment/stalking....... with the BBB in their city.