How did he pay, Paul? It's a ludicrous amount of money and speaking to the card issuer/bank might at least prevent the next two payments from being taken.
There is a nuisance call phone, which featured on Dragon's Den a while back - fabulous bit of kit, and that was retailing for around one year's payment for this service. Also many new "house" phones have the facility to block numbers from calling.
Or my personal favourite, answer, put it on speaker, put it on the table, carry on with your day.