Like the title says I switched my account to Monzo and it fully switched on Tuesday. On the same tuesday, I paid for an Uber which was still linked to my old bank. The balance on this bank is now showing -£9 - why hasn’t it just been taken out of my Monzo balance which has funds? I thought my Santander account had been closed? I’ve already tried “paying” my old account using the details and obviously the money just redirects and pays myself into Monzo.
Card payments won’t redirect. You need to call Santander and arrange to pay the money back. It’ll have seen this situation countless times before, but do it as a matter or urgency or there’s a chance you’ll now have an unauthorised overdraft which will be accruing charges.