Turn around time not true

I bought a built in cupboard on the 28th September. It was delivered the following day on the 29th. When i got the item my mother realized that it's not what she was looking for. She asked me to take it back. I had to wait for the item to be updated on their system as delivered for me to request for return. They have a policy of 7 days return. I have sent them the images of the item to show that i never opened it. It us still sealed. I have been waiting for them to come and collect but everyday I am told to wait for 24- 48 hours. This morning I was told that there is no guarantee for refund though I have not opened their item. And my mother had already bought what she wants from another store. Everyday I have been begging them to come and collect so that their 7 days policy will not expire and I will be penalized but I am not getting help. It took them less than 24 hours to deliver after I bought it but to return it it's now going to be more than a week.