In case you weren’t aware, the Federal Trade Commission maintains a document of legal does and don’t at https://www.ftc.gov/tips-advice/business-center/guidance/complying-telemarketing-sales-rule.
As of June 13, 2016, it is no longer legal for call centers to accept payments from consumers by remotely-created checks, remotely-created payment orders, cash-to-cash transfers, and cash reload mechanisms.
So, if use any of these for your telesales campaigns, now is the time to change.
On the other hand, if you’re a consumer and a telemarketer tries to get you to pay using any of the above methods, just say no. This is for your protection anyway, as most legitimate organizations use credit cards or PayPal to accept payments.