South Bihar Power Distribution Company [SBPDCL] — Bill related

My consumer no is [protected]. Name md sultana. Division - bihta. My april bill is inr 364.in april bill previous meter reading is 4143 and current reading is also 4143. So difference is 0 (Zero) but it denotes 28 unit and i paid the bill 364.
Next month may bill reading is 4143 and current reading is 4310 so difference is 167 unit. May bill denotes 167 unit but my april month 28 unit bill didn't discount in may bill. Please discount my 28 unit bill.