Avionco Canada Ltd review: They asked for training expenses, but I already paid for it

I recently returned the whole sum for the training program to the company Avionco Canada Ltd. After 4 days the rep from this company called me and asked to return this sum. I already sent them the proof that I paid for the training, but these jerks didn’t believe me and continued to ask for money. I wonder if there are people, who faced the same problem? I really need help or any useful advice. Please, post your comments and ideas. Thanks.