online service and return is shady

i bought a sneaker online, it arrived after a full week, after tying it opn, i realised that the shoe was a size bigger, so i called them to explain to me and also asked them how the returns process worked, the lady said she would the right size for me, and when the return is received on their end, they will then send me the right size, it took them another week for them to fetch the return, infact i had to call them to follow up on it, return took another week to get to them and because the process was taking too long i decided to call in again today to find out what the progress was, now all of a sudden the return is declined because the shoe was dirty inside and on the sole, when i received that shoe the soles on both shoes were dirty, but i didnt tell them all of that, considering how long it toook fo them to deliver my order, now i, told i should have called in and explained to them that the shoe was dirty, i mean really, like that was going to make a difference, the online service is very poor and you dont get much help unless you call in, i seriously dissapointed because i have not worn that shoe at all, and right after i realised it doesnt fit, i called them to let them know but now its suddenly in bad condition

something shady is happening in those warehouses, i want my money back or the right size, this is nonsense... i will never buy from you guys ever again.