Disappointing service from IdealPrepaid.

I own a rented house with 2 prepaid water meters bought from IdealPrepaid. Normally, the tenants buy prepaid tokens for water, the money is paid to IdealPrepaid, and each month, IdealPrepaid is supposed to credit my account with the money that the tenants spend on water, as I pay the municipal bills for the house. For the last four months, IdealPrepaid has not paid me any of the money they should pay me. Through my communications with them, they acknowledged that they owe me and agreed to pay. I have made several follow-ups with them, yet they have not paid me. Last Monday, I went to their office in person and they assured me that the payment had been released and that at the latest by today Friday, I would have received the money in my account. Today is Friday and I have not received the payment yet. I am very disappointed and cannot understand why they won't pay me money that I am rightly due. I even do not understand why they would hold back my payments for up to four months. I need answers to these questions.