Buffalo Logistics - worst courier ever delt with

I ordered from Temu and initially all went well and received my parcel 12 April, on the same day I initiated a return. The Monday morning, while already at work the courier told me he is on his way to collect, so I requested that they come a bit later as no one was home, he said he can't and will arrange with head office for a new collection date, which never happened. I sent Buffalo emails, with no response or an email 2 weeks later informing me my package has already been delivered on the 12th of April, I contacted them telephonically with promises I will be called back, no one ever did. 2 weeks later I canceled the return and initiated a new return as per Buffalo call centre agent's instruction. A week later my parcel was collected and when I asked the courier should I get some proof that the package was collected or sign anything, his answer was, No I will put the details on the package it goes to the same place anyway. So I asked how they wil know the parcel belongs to me and again he said, the sticker is in the vehicle, he wil put is on the package. Another week later a got a whatsapp from on of the delivery guys asking me when he can collect the package, so I told him it was already collected the previous week and he responded with a thumbs up. Since then I have been trying to find out from Temu and Buffalo express where the package is. Today I was told by Buffalo I cancelled the return on the 13th of May, but on Temu it is pretty much still open as a return. I am at risk of never receiving my refund and to me it is a lot of money. No one can seem to find my package and Temu is just referring me to Buffalo. Unreliable, no support, worst service ever from a courier company.