Ifb Washing Machine Dper Issue — Dper error frequently.. multiple complaints raised with IFB but no solution

Hi,
IFB front load washing machine shows dper error quite often. I have raised 4 complaints in the past 3 months.. the technician who comes to check simply using the drum washing powder and leaving .. it's working at times again the same problem. I have installed water softener, once in 2 weeks drum cleaning with IFB machine powder and using IFB liquid detergent for washing clothes. Still this issue occuring..can i please expect a permanent fix. If there is any issue with drain pump why can't the executive replace it? I still have warranty but the executives are not at all speaking about part replacement if any..