Incompetence from the people at ARAMEX Global Shopper (AGS)

I sell an artist paint which is non-toxic, odourless, NOT flammable and contains no oil. Therefore when I ship a parcel overseas, I always include the Material Safety Data Sheet with the shipment. I'm very aware that regular oil paint is flammable and should not be transported by air and I don't have a problem with that. I'm always for safety, especially when lives are at stake. However I have shipped it with ARAMEX before and in spite of the fact that my products are completely safe, I keep having to take a tub with me to prove that it is NOT a liquid, and does not burn. This morning, before taking the parcel to ARAMEX, I phone them and was assured it would not be a problem. I met the guy at ARAMEX, in the street outside their premises, handed the parcel with all the correct documents etc., explained, again, what it was that I was shipping etc etc. To cut a long story short, I was assured that all was in order and it would be dispatched promptly. I have just received an email from my client overseas, saying that she received an email from ARAMEX saying that the package had been rejected because it contains a liquid. I will collect it 1st thing in the morning and send it by another carrier. The people at ARAMEX are totally *********** and have no idea how to handle customers. When you deliver a parcel for shipping, they don't even let you (The Customer) through the gate. You have to wait until it is convenient for one of them to come and meet you in the street. I would never touch them with the proverbial barge pole and will be cancelling my account with them with immediate effect.