Never heard of it in the UK although we know it is done in the U S, I think the Brits are too concerned about the cost of a phone call, imagine you got someone talkative - the cost would go up and up...
They usually did a phone witnessing night on Wednesday's at the hall
No way would a British congregation pay the phone bill for that!
Letter writing by those who could not get out was done, but the congs got concerned about the quality of the letters from elderly ones...