Quiry a with return to myperfume shop

I used to buy and enjoy the services of my perfume shop, until recently when I returned a perfume which was not what I was expecting, I was asked to courier back the item at my cost, and it was confirmed received by them, since the 22 December they have been giving me a runaround about my refund, I requested proof of payment of them processing a refund, to date they are taking me from pillar to post, I am so disappointed cause I really used to appreciate they service up until now, and the problem is tem lying about the refund.