Doubtful donation

I have recently made a donation to a UK charity.

However because of previous difficulties with its tax position (it had wrongly attributed gift aid to certain funds it had received) the charity is now taking a very strict line with future donations.

In my view (and this has been informally confirmed to me by a specialist barrister) my contribution does qualify for gift aid but the charity is refusing to claim the additional tax relief on my donation.

Does the charity’s attitude prevent me from claiming tax relief on my own tax return? I propose to explain the circumstances of my donation (and the charity’s attitude to it) in the white space of the tax return to avoid the risk of a discovery assessment.

If I cannot validly do this how else can I force...