Teamwork?!

What does the word and the concept of "teamwork" mean to you? In the course of my duties I have to collate and receipt the payments relating to my division which then go through to a general accounts department. I had four payments last week and upon enquiring at least two times if everything had been paid received a resounding 'yes'. But one of my creditors emailed me to say he hadn't been paid. So I asked again if all payments had gone through and again the answer was yes. I got the lady to access our bank account and check if the payment had gone through and no - it hadn't. So now despite all my best intentions to stay calm, I start to steam up. Now when I go through to enquire - everyone knows suddenly that the particular payment I was enquiring about didn't go through. It wasn't an original invoice and there was an alteration. So what did they do. They just tossed it spitefully back into the payments pending drawer and didn't say anything. I could have rectified it from Friday last week onwards because our accounts department is now closing for the Festive season but because it was left I probably will now battle to get that payment through. This is not the first time this has happened and although it is a small thing it is part of the bigger company picture of why I am definitely ready for a change of scenery after almost 5 years (I need a medal!) with this company.