Buffalo Logistics Poor Customer Service

It has been officially 2 months since notifying Buffalo Logistics of the double payment made (accidently) for 1 order/package received. I attempted to send multiple emails and sent messages on their WhatsApp Business Account informing them, and requesting reimbur*****t. I supp**** them with all the relevant documents as proof of the double payment and no word, no email, no messages, no telephone call. When calling their customer care line, the call either gets dropped, or you are no. 100-and something in the queue on the line. I do not know what to do anymore, highly frustrating.