It is quite clear that Amazon use the “we will refund you in 5 to 7 days” to increase their massive profits and high cashflow.
I had a delivery from Sainsbury’s today. Some of the items were substitutions and were rejected. That refund is already being processed by my credit card company and shows up on my account as “pending”. The Amazon transactions are nowhere to be seen.
Clearly Amazon delay the refunds to just make more money from the customers who actually pay their wages.