Delays Due to No Customs Clearance Invoice

My package cleared customs on Wednesday 12 August, I phoned Fedex because I saw there was a customs hold. The person I spoke to said I would be emailed a customs invoice shortly and double-checked my email to ensure I could get the invoice.

Thursday came around and I had still not received any invoice, yet my item was on board the vehicle for delivery. The delivery failed because they didn't receive payment, yet they had still not sent me the invoice.

On Friday I phoned Fedex to find out what was going on and was then provided with an invoice to pay. I made an immediate payment on Friday and sent notification to the both the main Fedex account and to the person who sent me the invoice.

Then on Sunday morning I receive a second invoice email, from another worker - the day after I'd paid and sent POP.

I have still not received any confirmation of payment and the package status is still "At local FedEx facility".

I should have been sent the invoice on Wednesday and my package should have arrived on Thursday. Instead, I have no idea what's going on with it, when I should expect it. All because I wasn't sent the invoice until I phoned them to find out what was happening.