Missing parcel from Buffalo

I ordered my oder on shein on the 26 of october ....the next thing on the 4th of november my parcel was on transit which means it was scanned into depot .then from there when i checked my phone boom on the 12 of november it says my order was delivered and by that time18:18 it was on sunday .which by then there are no deliveries on sunday ...and on my track there is no sign in picture that it was signed .cos my previous orders came and when i track them they show sign in picture and where it was signed .i have been trying to call them everyday they just give me one answer that my order was delivered and I've signed for it .and by sunday i was at work how is it possible that I've signed for it .I've even emailed them everyday they doesn't help or atleast check who was delivering my parcel and ask them.i emailed shein and it said my request is still in process .i just can't deal with this i want my money back or else I'll email x-repo to help me because i have all the prove .