Formatted Select Query

Question

The following select query returns data in green.  How do I format to return the way it is formatted in red?
Basically, If FIELD1 is 'Customer A' and FIELD2 is 'Gas' then I want to return 'New Customer' in FIELD1 and 'Gas' in FIELD2.  If FIELD1 is 'Customer E' and FIELD2 is 'Total' then it should return 'E Discharge' in FIELD1 and 'Prod_Discharge' in FIELD2.
Please let me know if my question doesn't make sense or need clarification.
SELECT
DECODE(FIELD1, 'New', 'A', 'Old', 'E', 'Term', 'F', FIELD1)
,DECODE(FIELD2, 'Prod', 'Gas', FIELD2)
FROM Customers
FIELD1                  FIELD2   
Customer A           Gas          
Customer A           Oil     
Customer E           Total          
Customer F           Total   
Need to format as follows:
FIELD1                  FIELD2       
New Customer       Gas          
New Customer       Oil      
E Discharges         Prod_Discharged          
F Discharges         Prod_Discharged

Answer 1

I have added two fields, CustID and Status, to the query and get an error  "FROM keyword not found where expected"
SELECT
CustID,
CASE WHEN field1 = 'Customer A' AND field2 = 'Gas'   THEN 'New Customer'
            WHEN field1 = 'Customer E' AND field2 = 'Total' THEN 'E Discharge'
          ELSE field1
       END AS FIELD1
     , CASE WHEN field1 = 'Customer E' AND field2 = 'Total' THEN 'Prod_Discharge'
          ELSE field2
       END AS FIELD2
'Status
FROM Customers