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.
I strongly recommend that you talk to your department chair and ask for their help.
The situation as I understand it is that you obtained confirmation in writing from university employees that the equipment you wanted to purchase would be covered by the grant and you would get reimbursed. Now the institution is refusing to reimburse you. This is pretty unconscionable and sounds like a screwup on the side of the relevant officials.
It is the job of the department chair to try to help you resolve the situation and get the people involved to either find some way to be flexible about the stupid inventory issue (I am reasonably optimistic that if somebody beat them over the head with a hammer they would suddenly find some magical way to make it happen), or own up to the mistake and find some other way to cover your financial loss. The chair may also end up deciding that the department should absorb the cost if the reimbursement issue is truly unfixable.
Finally, before you talk to the chair I suggest carefully examining your own role in the events that took place and thinking about whether your own behavior might be seen to have played a part in this misunderstanding. Did you communicate your question clearly in the emails you sent? Did you miss some ambiguity in the email thread about whether it was okay to go ahead with the purchase? Did you make any assumption about the meaning of what the employees wrote that wasn’t explicitly written in their email (say, interpreting “research equipment” to mean “whatever I think research equipment means”)? If there was some negligence of this sort on your part, the chances of getting the purchase reimbursed would be much smaller. In that case the best thing to do may be to suck up the loss and use the experience as a lesson for the future. Anyway, good luck!
In my experience in the US, computers and their parts are considered part of overhead, as are things like desks, office chairs, etc.
When you get a grant, part of it goes to "you", and part of it goes to the university as overhead - they use this to keep the lights on and for other various expenses that you don't directly see, but they also often make some of that money available to the researchers to buy capital equipment including computers.
It's unfortunate that you got incorrect information due to a miscommunication, but it's likely nothing can be done about those funds directly. It's possible there is overhead money that can help you out retroactively, but I don't have experience with that circumstance.
From my perspective, this looks bad for you - it seems like you tried to skip around the "has a hard drive" rule.