A bad taste in my mouth

I've had a very bad experience with puma and this is the last time buying from them. On the 22nd November I placed an order for 5 tshirts on their black Friday promotion and when I had not received anything I sent them a mail advising them. They then declared my order missing and now they dont want to send me a replacement but are forcing me for a refund. I dont want a refund but a replacement for my kid's clothes. I've been going through this for more than a week now.