Reliance Communications — Regarding 4g wi pod

Address:

Kanchipuram, Tamil Nadu, 603103

I am a postpoid user recently i got my 4g dongle in the mid period of dataplan and my credit limit is₹ 2500 but as i got mail stating that my bill due ₹24024 they didnt any proper communication prior. Now they asking me pay that amount. Previously i am using 999 pack of40 gb unlimited data. I thought same plan will be continued for my4g. As it was too huge i am in a confused situation.