My complaint:
I made a withdrawel from a Betting account of £36 as I wanted to spend it elsewhere but the withdrawel was declined by my bank (Monzo) after a live chat with the bank they told me that Mastercard had declined this as possible fraudulant activity. This is annoying as its taken 3 days with trying to get htis sorted. it was meant to be a quick transaction. Seems your algorithemsrules are quite poor.
Suggested solution:
Should have a process where you can verify with the card holder to check that this is legit, it gets annoying the amount of time wasted on these sorts of problems. Now I have to wait a couple of days to see if it will bounce back to the bookies or waste time with their accounts dept