The debit card I use to top up my Mondo card has expired, so when I wanted to top up £200, I first added the new card (Smile/Cooperative Visa Debit). When I entered all the data, I received an alert telling me ‘Your card has been declined’. I then checked the details (all was correct, I didn’t change anything) and tried again with the same details. This time it went through. However, the new card total was £428.23, whereas I expected it to be £228.23. The payment had gone through successfully.
Hey Mike, sorry about that! Best bet for things like this is to start an in-app chat with customer support 
They’ll be able to get it sorted in a few minutes
Thanks Tristan, it was more of a bug report rather than a cry for help 