Your terminology is confusing.

You aren't receiving a refund to your initial form of payment (i.e. credit card) but a voucher to be used in the future with IB.

I know that IB have long had stricter rules about cancelling for a voucher than BA - and they certainly appear to have loosened the rules substantially - but calling it a "full refund" is misleading. When people call up for a refund, they want their money back, not a voucher for future travel that expires in 14 months...