Purchase return under gst

GST EXPERTS PLEASE HELP!!!

I WANT TO KNOW WHETHER MY ACCOUNTING TREATMENT FLOW FOR PURCHASE RETURN IS CORRECT

I MAKE A PURCHASE RETURN IN THE MONTH OF JULY TO MY SUPPLIER HE DOESNT ISSUE ME A CREDIT NOTE WHICH REFLECTS IN MY IMS DASHBOARD, HOWEVER I VOLUNTARILY REDUCE THE ITC IN THE TABLE 4(B)2 OF ITC REVERSAL IN THE 3B , NOW WHEN AUGUST MY SUPPLIER FILES HIS CREDIT NOTE IT SITS IN MY IMS DASHBOARD I SIMPLY ACCEPT THE CREDIT NOT BUT WITH "NO" FOR REVERSAL FEATURE THUS THIS DOESNT REDUCE MY ITC TWICE PLUS MY SUPPLIER GET THE LIABILITY SETOFF FOR THE RETURN I MADE 

IS THIS CORRECT PLEASE HELP