Tenant has withdrawn money from my account instead of depositing

[Nahal Beckam]

Hello, I asked my tenant to pay the rent online. Gave him my wells fargo bank account and routing number. then he said his chase bank has sent me two small deposits to verify my account. so I gave him the amounts of the two tiny deposits and he was able to pay me rent. This month I see a  pending withdrawal instead of rent deposit in my wells fargo account. I asked my tenant to cancel the withdrawal and make a deposit instead. but he says he only sees a pending deposit to my account that cannot be cancelled. I called my bank and they said we can only place a dispute which can take up to 10 days to resolve. Now my question is, does my tenant have access to my account and can withdraw money from me, or it is a bank mistake? has he fooled me by asking for those small deposits value? maybe he has linked my account to his own and can access my money. please help what I should do.