Sports Direct returned 4 items only refunded for 1

m4r14j

I bought 4 pairs of hiking shoes from sports direct 3 weeks ago when I realised my old ones weren't up to the job just before going on a walking holiday. I bought 3 styles in various sizes.

None of them I liked or were comfortable so the same day they arrived I put through a returns and sent them straight back within hours paying £4.99 through their returns label print service as instructed on their website. It was some sort of 3rd party shipping but went through the evri system. The parcel was large and well taped up in packing tape as you can imagine from 4 shoeboxes all next to each other.

Now they are saying I only returned a single pair of shoes from the order and are refusing to refund me the full amount. I'm down over £100. They say they checked with their warehouse team who confirmed I returned a single pair of shoes in an undamaged parcel. When I check the parcel through Evri however it still says in transit but not confirmed delivery yet.

What can I do to prove I sent them all back? Or how can I get my full refund? 

Thanks for your help in advance