Managing credit cards

Managing credit cards

Hi,
I'm hoping someone on this forum can help me out managing credit card accounts. 
Transaction are entered as expenses using the credit card account and, as expected, the card balance shows as a negative since this is clearly money I owe them. 
Once I make a payment, of the full amount owed, I woudl expect the balance to become zero. It doesn't, the negative balance just keeps on increasing even though the payment is reflected correctly in my main operating account. 
No-one at Zoho seems to understand the issue and is telling me that's how it's meant to perform. 
If it's me doing it wrong (I'm new to Books) then I'd really appreciate any guidance. 
Thanks,