Institution refuses reimbursement for grant awarded? After managing a project at a research institution in the US, I was awarded a grant (did it for free, so this is the remuneration). The grant covers travel, books, research equipment ("that does not contain a hard drive") and some other things. They strongly recommended confirming with their representatives if certain expenses are covered by the grant. I decided to purchase PC components and just build it myself. Last August I contacted them to check if they would cover the components cost (2 reps said it should be fine, both were in 1 email thread). Over Black Friday I purchased all parts and sent them all receipts for reimbursement. Now, middle of January, they claim they did not realise I was building a PC (although I explained everything in detail in our email communication back in August) and would not reimburse me as the institution tracks parts "as part of their on campus computing inventory". It is past return period time now for the components I purchased. What should I do now? All communication was over email, so I have everything in writing.
What you need to do is work it out locally. If necessary, the grant funder may need to make a judgement. But it seems like you were trying to get around a restriction by somewhat questionable means. Not necessarily ethically dubious means, but questionable. A pedantic interpretation of the statement in the grant, and ignoring its likely intent is what got you into the current situation. You need to argue that your interpretation is correct and you need to get others, who have some authority here, to agree with you. 

I can't guess whether you will win this or not, but the situation is between you, the institution and the funding authority. Make your best argument there. And note that you can't impose your own will on this. 

If this is PC level equipment, I doubt that it is going to be a serious setback to your finances. Maybe it is best to just absorb the cost and spend the funds on things that aren't so close to the margin of acceptability.