The first thing to do is to stop playing this slot and contact the representative of the casino. This is easy to do, as all casino sites have a support chat. There you will need to answer questions and support will be able to help and explain what happened and why.
Many top online casinos provide new players with no deposit bonuses for completing registration. The no-deposit amounts rarely exceed $10. The wagering coefficients often reach x50.
If you are not experienced enough in this matter, trust the gambling professionals. Read reviews of online casinos on the casino review section.
When transferring over $1000 or the equivalent in another currency, bank employees can transfer transaction data to the tax office. They will try to find out the origin of the money and the payment of income tax.