Need help.

Previously received a call from TM saying that my account have outstanding balance that I need to clear otherwise they will cut my internet. I don't believe him so I went to the nearby TM point to have them to take a look at my account. But for some reason there are outstanding balance for about 2 months worth.

Fine, I paid them. A few days later I received a call from TM also saying the same thing and if I don't pay, they will cut my internet. I told them i've paid and they say their system still show the 2 months worth of outstanding balance.

What will you do? I never miss paying UNIFI bills so far.