"It was disgusting behaviour. I was disgusted with his actions, as there's a shopping centre near which has eating facilities which he could (have) used to go to the toilet," she told the publication.
"I use Amazon, and have actually let one of the delivery drivers use my bathroom — they only need to ask.
"I know he delivered an Amazon parcel to my neighbour. I was watching him from my bedroom window."
Lumbard said Amazon confirmed it was looking into her complaint as a "matter of priority".
"I just had a call from Amazon and the guy said the driver has been dealt with, whatever that means, he didn't say," she told Metro.
"And they apologised for the driver's actions. I expect he'll do it again."
However, Amazon later told the publication the driver had been sacked.
"This does not reflect the high standards we have for our delivery service partners," the spokesperson said.
"The driver will no longer be delivering on behalf of Amazon."
However, it's just the latest in a string of incidents involving Amazon delivery workers.
In a separate incident in September, an Amazon delivery man was caught on film carelessly lobbing London customer David Jacobs' fragile item on to his first-floor balcony.
Jacobs shared the alarming footage on LinkedIn, where it quickly went viral and sparked widespread outrage.
And in December last year, an investigation by the Sunday Mirror alleged Amazon drivers regularly worked shifts that exceeded the UK's maximum legal limit of 11 hours, with overworked employees forced to urinate in plastic bottles on the road in an effort to keep up with the delivery demand.