How can I pull somebody with just a payer order 9 in payer order column?

Result I would like to have:

I am trying to pull customers that only have a payer order 9 payer name ginny, they can not have any other payer order attached to them. The issue I am running into is all customers have a payer order 9 payer name ginny. As you can see the billing order is not always a simple 1-8 listing, as depending how it is put into the system, they may not use billing order 2 but skip to billing order 3. How would I go about grabbing just customers with billing order 9 payer name ginny? I would say the ginny isnt needed in the sql due to payer order 9 will always be payer name ginny.

I did try doing:

WHERE payerorder < 9 AND payername is NULL 

Which ended up not working, it would only pull one row that had a payer order but a blank payer name but the customer, when I checked the profile, still had other payer orders like 1,3,5 with payer names.

I also tried:

payerorder = 9 and payername = ginny 

But the issue with that is everybody has payer order 9 payer name ginny. I only need to pull customers who only have payer order 9 and payer name ginny.

Edit: new post with updated information

One method would be to use an EXISTS to check no rows for that client exist with a value other than 9:

SELECT DISTINCT
       YT.CustomerID,
       YT.payerorder,
       YT.payername
FROM dbo.YourTable YT
WHERE YT.payerorder = 9
  AND NOT EXISTS (SELECT 1
                  FROM dbo.YourTable E
                  WHERE E.payername= YT.payername
                    AND E.payerorder <> 9);

An alternative method would be with a HAVING to check the MIN and MAX values are both 9:

SELECT MAX(YT.CustomerID_,
       MAX(YT.payerorder) AS payerorder,
       YT.payername AS payername
FROM dbo.YourTable YT
GROUP BY YT.payername
WHERE MAX(YT.payerorder) = 9
  AND MIN(YT.payerorder) = 9;