Is mobile main OTP nahi aa rha hai sim card dusre mobile main dalte hai to OTP aata hai lekin is mobile main OTP nahi aa rha hai

I bought Zen mobile Z8 Rocker in October 17for my mom.
From the first day after bought this mobile there is a technical problem Goud in mobile that after switch on /of the Z8rocker mobile all data disappear for next few hours some times after receiving incoming call after talking when we end call by end button it could not cut.
I so many times take the Mobileto device centre but always have accuse that he don't have essential software to solve the mobile problem and I always not get positive fever from your service centre in yashwant plaza indore
So kindly help me what I am do now?
because the technical problem is same as by the first day

Mene 2 ticket booking kiya tha but 1 ticket conform hu. Our 1 ticket TQ|WL1 me sala gaya

Hi , my Zen mobile M72 body is damage but nobile is OK ,plz contact me if arrange body my contact no 9039593805

Hi , my Zen mobile M72 body is damage but nobile is OK ,plz contact me if arrange body my contact no 9lllllllll

Humko zen mobile phone ki thuch cheng karbana h