Debt Collectors claiming Exorbitant amounts to be paid

Good Day

Someone from your legal team emailed me and advised that I owe R1595 on my total and final balance but your supposed debt collector Saya recoveries who I have never made a payment to before says that I owe R5444.

I have paid what I could afford month after month to MTN directly, I have been unemployed a few times during the past couple years but always made somewhat of a payment monthly.

I have never used the airtime or services on both MTN numbers due to poor signal and one of the phone's was ******.

Please clear up this matter and come back to me with final amount owing because I do not recognize that I owe Saya Recoveries any money.

I have paid MTN alot of money for just using 1 phone. I want to wrap this account up!