Sentence is not enough to accuse them as scam, you need valid evidences to support your allegation. 10k USD is not small amount of money so you must have at least an evidence for that amount. Your betslips can be one of the evidences that you can provide here or better for you to create a scam accusation thread in this board if you have valid evidences and dont forget to read the sticky thread on how to create a scam accusation (simply follow the format given).