Begging for Invoices

Each time I receive a quotation from Nonhlanhla Mthembu and pay for the goods immediately, I have to beg and plead for up to 6 days for my invoice to be emailed to me in order for me to collect the goods from the warehouse. The warehouse staff, understandably, can't give you the boxes if you present them with a quotation. I fail to comprehend why the invoice can't be sent to me together with the email acknowledging receipt of my payment?! It's happened more than once and I'm frustrated beyond belief. The telephone systems are sometimes so bad, my call gets cut off 5 times before I give up trying to speak to someone to resolve these issues.