Made a cash deposit at the bank.

Transaction showed in 'Banking'.

Went to match the relevant invoices to the transaction.

I'd recorded an invoice amount incorrectly so the total of the invoices didn't match the total deposit at the bank.

Came out of 'Banking' and screen pop up said 'do you want to discard this transaction'. I hit 'yes'. Went to invoices, changed the incorrect one, went back to 'Banking' and my transaction showing the cash deposit at the bank has disappeared!

Have left it 3 days so 'Banking' can sync again a few times with my actual bank account. It has but the cash deposit transaction has not reappeared. 

Has anyone any idea where I went wrong and how do I rectify this, please?

Many thanks.