Dissatisfied with product return service

I have been buying online from Decofurn for many years. Their quality with some exceptions are generally acceptable for the purposes I have purchased it for - understanding that it is a venue for affordable furniture. I submitted a very big order in November 2020 for delivery at our guest house. It included 14 pedestals. After building one which quality was fairly low but accepting it is what you get at that price range, I realised that it will not work in my guest house. I could not find an alternate product to exchange it for and requested a return of the 13 unassembled pedestals which I logged on 9 Dec 2020, which they said they will collect at a charge - so it is not a free service to return unlike other online shops. Despite follow-up my returns have not been collected more than a month later and in the meantime I sit with a product out of which I will get no use but they have the benefit of the money paid for it. They are very good with online purchases and deliveries of purchased goods but obviously very poor in returns. If you offer the service to collect you need to deliver the same service as for purchases. After every follow-up I get a response that it will be collected asap but I am waiting and waiting. A very frustrating thing about all online shops is that they offer no post-sale contact numbers or telephone numbers or interactive chats - it is very frustrating and disappointing.