Entering payment with STC rebate

Hi, can someone please advise how to enter this correctly. (For context, small community club outsourcing accounts to me. I allocate everything through bank transactions, don't use suppliers or bills. Minimal invoicing.)

Client purchased a Solar system, this was invoiced at $22,000, gst $2000 (not real figures but correct ratios). STC rebate of $7000 was deducted GST free, invoice total paid was $15,000, gst $2000. I've already checked with the electrician that this is how he usually invoices. When I'm preparing the BAS I have the $22,000 coded as CAP, then the STC rebate negatively coded as FRE, I guess the figures all add up but it doesn't look right on the GST report that the STC rebate is deducted from the GST purchases? Thanks