Nilkamal — wrong mattress sent

Address:

Madhapur, Hyderabad, Andhra Pradesh, 500049

We purchased a cool nilkamal mattress from @home by nilkamal, at the time of purchase wentold them our size is 6*6 king size, bt what they gave us was 6*6.5
They have taken tht mattress back and now when we are asking our money refund they are telling us to take credit note.
We are not tht rich that we spend our mattress money for something else tht we don't want.
Please arrange for our money refund