Old khaki useless online store

What a disappointing online experience. Went online ordered two shirts which showed available on their system, one shirt was R399 the other was R349 Total R748 so I had a voucher of R100 which I used and payed R650.44 so when they sent the order I received one shirt of R349 the other is out of stock no one from old khaki called to let me know if perhaps I would like an alternative I had to be the one to email and find out why are they sending one shirt when I ordered two, they reply by saying out of stock mind you on the app it was in stock, and it will take days to have it sorted out I opted for a refund as this is a gift for my husband I was disappointed. Now that they have refunded me no one called and communicated anything I just get a bank notification of R299 refund for a shirt of R399 what about the voucher used? Are they not supposed to ring the voucher with the available shirt and refund me back R399? Now they have R350 for the one shirt and my R100 voucher on their system for an order of R350 basically I paid R450 for a R349 shirt they don’t even offer me back my voucher of R100 which I can still use. The worst online store can you refund me back my R100 or give me back my voucher