You want to go straight for these numbers that are instant answer and no ivr menu to listen to.
There is a thread a listed the numbers that remain active for half an eternity.
I find large amounts of these huge mailout voucher call centre numbers quite often.
They last for a few months then they move to to brand new number homes.
There has been two more numbers for these idiots my dialers picked up today but that’s enough to keep the enthusiast retail rebate voucher teasers in their element for days.