Faulty Items sold on Aliexpress

I bought a diagnostic tool on Aliexpress through Seller CARATDIAG Store. The software on the tool was ******* so I was not able to use it. The Seller agreed to refund me as soon as I return the item, I must just send him the tracking number and he will refund me. After doing that he changed his mind and said he will refund me as soon as he received it. I logged a dispute on Aliexpress but they did not refund me as to them the unit was not physically damaged and the Seller did not yet receive the parcel, I attached all proof of shipping.