Ferns N Petals — Money transfer

I booked an order in march which said there was a failure with the money transaction but in my bank the transaction already took place and there is a reference as well which I shared with ferns and petals
My bank requested for beneficiary details from ferns and petals and statement with logo which ferns and petals kept denying to provide as they believe that transaction didn't take place . But clearly in my bank transaction it shows there is a transaction.
To resolve the issue I just need the document to check what happened to my money and if ferns and petals didn't receive the money I don't think it's pain to help a customer who been so loyal to them for years