They ****med me my money for their word office while they know that is not working

I registered word office with them, of which it was not working on my side I sent them an email saying their word office is not working they said they will get back to me and they didn't, all of surden after two days I receive a notification that they debited my account an amount of 255 zar, i sent them an email again asking for a refund and they said they will refund me within 24 to 48 hours which is now over that, yesterday they sen tme an email saying the apologies they won't refund, why can they refund me cause I informed d them in time, all I want i my money back