Paytm - Paytm post paid

on **-**-**** I did the last Paytm postpaid transaction payment (OID ********** TID ******************* Amount ****.**)
But, as I was late by few days after that the very account was blocked and from that day I could not use postpaid service, fair enough I was a defaulter after all.
But on **-** -**** after about * months of paytm postpaid inactivity I get a call to clear post paid amount ****.** (OID ****************** TID *******************)
that didn't do..... that to at a pharmacy store as they told.
despite telling them they still call and harass my contact list. the point is when post paid was blocked how can i use it in the first place.
strangely when i complained i got calls from spammers asking about my UPI pin and all. sensing fishy I reported that in tweet but still no response.