I’ve heard the switching providers thing and that it’s a scam to get your bank info. By showing them the invoice, you’ve provided them the account number, account holder name, address, amount due, and potentially a previous payment amount. When they ask for your contact info, you give your email and cell number. All of this can be used to hack/call customer service and gain access to your account and bank info. It’s a sick and twisted scheme that seems so innocent.