Installment plan

My services were interrupted due to a past due balance. I was informed that an installment plan was available for those in the same position, and in asking the eligibility requirements I was told by an agent that all that was required was to have a past due balance. With this being said, when I try to apply for a plan, I’m being told I’m ineligible. How, if the only requirement is a past due balance, am I ineligible for an installment plan?  This is highly frustrating as no one can seem to give a proper answer to my question. And if this is the only requirement, why are these plans that are supposed to be a supportive resource for those in need, so excruciatingly difficult to access?? It seems as though the company just wants to appear as though they are helpful by offering these resources with little to no intention of actually providing them.