Unable to get customs duties breakdown. Horrible service.

I ordered items from Temu and received the tax invoice for the customs duties that I am required to pay. The customs amount seems a bit high, so I attempted to contact Buffalo via various channels (online chat, support form, email, whatsapp, and phone) to request a breakdown of what SARS charged me for each item, so that I can cross check the SARS classification of the item and what the duties are for the classification. I just want to make sure that SARS didn't mis-classify an item and inadvertently overcharge me. Only for Buffalo to tell me to contact the supplier. I did, and Temu told me that they are not in charge of customs and cannot provide anything outside the list of items in the order, which SARS uses to calculate the duties. This makes sense to me. So I resulted to calling Buffalo over the phone, as the response time is quicker than all the other channels. Only for the support agent to tell me to contact Temu. How is the supplier supposed to give me the breakdown of the SARS charges? When I try explain that Temu cannot assist and that Buffalo should be able to request the breakdown from SARS, they just speak over me, brush me off, tell me that I need to contact the supplier and hang up on me. The contact centre seems like they have no clue how SARS works and give generic answers instead of trying to assist me. When I requested that they put me through to management, they tell me that the managers are not available. They don't even offer to take my number for a callback. The support will do everything not to help, and end the call as soon as possible, even if it means hanging up. None of their responses made any sense and didn't help in resolving the issue at all. They don't even seem bothered to listen to why contacting the supplier is not an option. They just hang up. Utterly terrible service from Buffalo.