Humbert don't hold your breath, the only way I got mine back was to call and ask for it. If you do a tax return you have to specify you want it back now!
I have calculated how much less I will get each month on my pension in order to pay the tax on my savings. The government will get the tax earlier under this new system and I will have to keep strict records of interest paid to me and to DH so we can check at the end of the tax year. No idea how that is going to work as I don't do a tax return. I do know I will be overpaying as we gave away a substantial amount last year so interest will be a lot lower. So glad I have Excel!