Coustomer service : my experience is pretty good regarding that.they have vry nice team which updates small moment in he app or website regarding ur login. Evry update is clearly mentioned and der is no need of hiccups for any customer.
Product Quality: it all depends upon third party seller who is displaying the product. My experience was little disatisfactory but its not all the time it goes wrong.
Delivery timeliness: yes as mentioned it is prompt. It dwpends upon courier/ logistics company which is delivering.
App & website: good interface evrything is fine bit nowadays we r finding less promocodes wer we wer finding cashbacks
Reliablity: good.
Note: paytm was in boom when it had good cadhback offers, but if thy continue to do promocodes for something which is like a lottery its gonna affect the popularity for sure.
Final verdict it a 2.5/5
It has seriously gone slow wit time.