I have also had an email offering to convert an outstanding refund to a voucher plus GBP30. I've had a couple of refunds thus far but as I have a booking to make for next year which is for almost exactly the amount in question I have accepted the voucher as I have nothing to lose by doing that.

As above, the voucher is valid for a year and you don't have to use it yourself and tickets can be booked in any name.