Mr. J needed his electric meter to be topped up and it was described in the email that this could be done at the Post Office, but unfortunately this wasn't the case. I went back and forth to find a Pay Point which accepted the voucher I received from Mr. J. In the end, I found an off-licence that could top up the key with the £30 voucher Mr. J received. I duly went back to put the key back into the electric meter.