Company not processing a refund. What legally can I do?

The company isn't disputing the returns or that they won't, just not doing it and their CS is non-existent. The goods that were received 05/06/2014 and 12/06/2014 and I have the receipts to prove it. They state in busy periods that they can take up to 28 days. The first return has now gone over this period and the second will do soon.

Phoned them and can only ever occasionally get through to sales who say they're pending and have done for the last 2 weeks. CS never answers phone or responds to e-mails.

What can I do to legally try and reclaim my money? Just want my £65 back.