WHMCS generating invoices for other paid invoices

[seancon1]

not exactly sure what has happened but i have 4 invoices (line item description is in bold)

 

Invoice #1705 = Domain Renewal - domain.com - 1 Year/s (05/05/2013 - 05/04/2014) - $12.99 with a Due Date of 05/05/2013

 

Invoice #1709 = Domain Transfer - domain2.com - 1 Year/s - $12.99 - with a Due Date of 05/04/2013

 

Invoice #1710 = Invoice #1709 - $12.99 - with a Due Date of 05/02/2013

Invoice #1711 = Invoice #1705 - $12.99 - with a Due Date of 05/02/2013

 

from what the client told me, they have a credit and wanted to transfer a domain and pay the renewal invoice, so i believe what happened is they logged in, purchased the transfer, went back to the home page without paying for the transfer, clicked pay all and it took them to the payment gateway without an option to use their credit.

 

the canceled and returned to the client area and paid each invoice separately which allowed them to use their credit.

 

this morning they received an overdue notice for 1710 and 1711.

 

i am thinking the pay all click generated 1710 and 1711.

 

 

trying to understand if this is client error, a bug or something else.

 

thanks

 

Sean