Hi there, new to Sage!

Our company recently made an order for marketing materials, paid for it, only to find errors with the materials.  The Vendor replaced the entire order, but also credited us the total bill.   So,  we had a credit with them at their online store to use for future purchases. 

We have since used some of the balance of the credit with several purchases. 

My question is.  How do I record the Store Credit in Sage.  I have already entered the initial purchase invoice, and payment from our MC.  Now I have other purchases to enter as well in order to track how much we actually bought. 

I have read through this site, and have not found an answer that I can understand.   I was about to post a Purchase Invoice Credit using a negative total, and putting it to the original expense acct.  (btw the credit they gave was not the exact amount as the original purchase)   But, then I did not know how to deal with the payment method.  and with the following purchases, how do I record their payments... since it is a store credit. 

I also read, that I could do it like a Gift Certicate or refund from the vendor, but i did not actually receive something to credit my bank back with... it sits as a Store credit with the vendor. 

I am confusing myself... sigh.