Do you mean a specific company named “Heartland” (for example Heartland Payment Systems / Heartland Payroll, Heartland Dental, Heartland Bank, Heartland HomeCare, or another regional Heartland business)? There are multiple unrelated companies called Heartland and each has different customer-service numbers, hours, and procedures.
Please tell me which Heartland organization (or give the website or city) you want covered. Once you confirm, I will produce the detailed HTML text you requested, with precise contact guidance, verification steps, common call flows, and practical tips.