How many times should I pay for 1 cellphone contract?

I had a contract with the above mentioned and due to lock down I was unable to pay so my account was handed over to Saya recoveries which as soon I went back to work (I even paid more than it was required to finish up)the account was closed to date I am still waiting for a paid up letter after almost 4 months now. To my surprise now I am getting SMS from nimble group to make payment arrangement and I called back Saya recoveries I was told the agent who was working my account left the company and no one else could .Nimble group line is forever ringing without an answer .